diff --git a/.github/FUNDING.yml b/.github/FUNDING.yml
index 1d270e7894..dbe0dc229a 100644
--- a/.github/FUNDING.yml
+++ b/.github/FUNDING.yml
@@ -1,2 +1,2 @@
 github: rustfoundation
-custom: ["rust-lang.org/funding"]
+custom: ["https://rust-lang.org/funding"]
diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
new file mode 100644
index 0000000000..8144ba3056
--- /dev/null
+++ b/.github/pull_request_template.md
@@ -0,0 +1,3 @@
+<!-- Before submitting a PR, please familiarize yourself with the
+[developer guide]([CONTRIBUTING.md](https://rust-lang.github.io/rustup/dev-guide/index.html)),
+including the AI policy and style guide. -->
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index f79ec050ba..f57ca6d789 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -202,13 +202,13 @@ jobs:
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           AWS_DEFAULT_REGION: us-west-1
       - name: Configure AWS credentials
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         uses: aws-actions/configure-aws-credentials@v6
         with:
           role-to-assume: arn:aws:iam::890664054962:role/ci--rust-lang--rustup
           aws-region: us-east-1
       - name: Deploy build to rustup-builds bucket for release team
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         run: |
           aws --debug s3 cp --recursive dist s3://rustup-builds/${{ github.sha }}/dist
         env:
@@ -401,13 +401,13 @@ jobs:
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           AWS_DEFAULT_REGION: us-west-1
       - name: Configure AWS credentials
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         uses: aws-actions/configure-aws-credentials@v6
         with:
           role-to-assume: arn:aws:iam::890664054962:role/ci--rust-lang--rustup
           aws-region: us-east-1
       - name: Deploy build to rustup-builds bucket for release team
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         run: |
           aws --debug s3 cp --recursive dist s3://rustup-builds/${{ github.sha }}/dist
         env:
@@ -606,13 +606,13 @@ jobs:
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           AWS_DEFAULT_REGION: us-west-1
       - name: Configure AWS credentials
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         uses: aws-actions/configure-aws-credentials@v6
         with:
           role-to-assume: arn:aws:iam::890664054962:role/ci--rust-lang--rustup
           aws-region: us-east-1
       - name: Deploy build to rustup-builds bucket for release team
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         run: |
           aws --debug s3 cp --recursive dist s3://rustup-builds/${{ github.sha }}/dist
         env:
@@ -776,13 +776,13 @@ jobs:
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           AWS_DEFAULT_REGION: us-west-1
       - name: Configure AWS credentials
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         uses: aws-actions/configure-aws-credentials@v6
         with:
           role-to-assume: arn:aws:iam::890664054962:role/ci--rust-lang--rustup
           aws-region: us-east-1
       - name: Deploy build to rustup-builds bucket for release team
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         run: |
           aws --debug s3 cp --recursive deploy/ s3://rustup-builds/${{ github.sha }}
         env:
@@ -948,13 +948,13 @@ jobs:
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           AWS_DEFAULT_REGION: us-west-1
       - name: Configure AWS credentials
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         uses: aws-actions/configure-aws-credentials@v6
         with:
           role-to-assume: arn:aws:iam::890664054962:role/ci--rust-lang--rustup
           aws-region: us-east-1
       - name: Deploy build to rustup-builds bucket for release team
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         run: |
           aws --debug s3 cp --recursive deploy/ s3://rustup-builds/${{ github.sha }}
         env:
@@ -1003,6 +1003,7 @@ jobs:
           - armv7-linux-androideabi        # skip-pr skip-main
           - x86_64-linux-android           # skip-pr skip-main
           - riscv64gc-unknown-linux-gnu    # skip-pr skip-main
+          - riscv64gc-unknown-linux-musl   # skip-pr skip-main
           - loongarch64-unknown-linux-gnu  # skip-pr skip-main
           - loongarch64-unknown-linux-musl # skip-pr skip-main
         include:
@@ -1146,13 +1147,13 @@ jobs:
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           AWS_DEFAULT_REGION: us-west-1
       - name: Configure AWS credentials
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         uses: aws-actions/configure-aws-credentials@v6
         with:
           role-to-assume: arn:aws:iam::890664054962:role/ci--rust-lang--rustup
           aws-region: us-east-1
       - name: Deploy build to rustup-builds bucket for release team
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         run: |
           aws --debug s3 cp --recursive deploy/ s3://rustup-builds/${{ github.sha }}
         env:
@@ -1272,13 +1273,13 @@ jobs:
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           AWS_DEFAULT_REGION: us-west-1
       - name: Configure AWS credentials
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         uses: aws-actions/configure-aws-credentials@v6
         with:
           role-to-assume: arn:aws:iam::890664054962:role/ci--rust-lang--rustup
           aws-region: us-east-1
       - name: Deploy build to rustup-builds bucket for release team
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         run: |
           aws --debug s3 cp --recursive deploy/ s3://rustup-builds/${{ github.sha }}
         env:
@@ -1403,13 +1404,13 @@ jobs:
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           AWS_DEFAULT_REGION: us-west-1
       - name: Configure AWS credentials
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         uses: aws-actions/configure-aws-credentials@v6
         with:
           role-to-assume: arn:aws:iam::890664054962:role/ci--rust-lang--rustup
           aws-region: us-east-1
       - name: Deploy build to rustup-builds bucket for release team
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         run: |
           aws --debug s3 cp --recursive deploy/ s3://rustup-builds/${{ github.sha }}
         env:
diff --git a/Cargo.lock b/Cargo.lock
index c4ab9ec825..08a6440acf 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -10,9 +10,9 @@ checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
 
 [[package]]
 name = "aho-corasick"
-version = "1.1.4"
+version = "1.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ddd31a130427c27518df266943a5308ed92d4b226cc639f5a8f1002816174301"
+checksum = "c982642fa9e8606056828ee9a8505737230110bb1099153c79efe865c59d12ba"
 dependencies = [
  "memchr",
 ]
@@ -76,9 +76,9 @@ dependencies = [
 
 [[package]]
 name = "anstyle-svg"
-version = "1.1.0"
+version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db7ec5fa88fc0837393f6b110b0764aeb0a673952bc91300628641dd0fffbf85"
+checksum = "ab68e0b71ea68eb6b399ffe1957f26330aeed91f5e578d442a1c2f3df69f6ec1"
 dependencies = [
  "anstyle",
  "anstyle-lossy",
@@ -100,9 +100,9 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.103"
+version = "1.0.104"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2a4385e2e34eb35d6b3efe798b9eb88096925d87726c0798709bf56d9ed84af3"
+checksum = "330a5ed07fa54e4702c9d6c4174f74427fc0ef6e214bbd677ae50a5099946470"
 
 [[package]]
 name = "as-slice"
@@ -115,9 +115,9 @@ dependencies = [
 
 [[package]]
 name = "async-compression"
-version = "0.4.42"
+version = "0.4.43"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e79b3f8a79cccc2898f31920fc69f304859b3bd567490f75ebf51ae1c792a9ac"
+checksum = "3976abdc8fe7d1133d43d304afd42abdf5bc3e1319d263d223bde07b5efc4be8"
 dependencies = [
  "compression-codecs",
  "compression-core",
@@ -127,13 +127,13 @@ dependencies = [
 
 [[package]]
 name = "async-trait"
-version = "0.1.89"
+version = "0.1.92"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9035ad2d096bed7955a320ee7e2230574d28fd3c3a0f186cbea1ff3c7eed5dbb"
+checksum = "82f6aeea286b8eb4dd3431a1be1b59d290ace00f5bfd8e2a159bc2a05e2c1667"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 3.0.3",
 ]
 
 [[package]]
@@ -150,9 +150,9 @@ checksum = "f2032f911046de80f0a198e0901378627c33f59ea0ac00e363d481118bd70a53"
 
 [[package]]
 name = "aws-lc-rs"
-version = "1.17.1"
+version = "1.18.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4342d8937fc7e5dd9b1c60292261c0670c882a2cd1719cfc11b1af41731e32ad"
+checksum = "ce2b2dcc879c3bae0d371e77c99f2238400ef24ec001394befa67b6e543add9e"
 dependencies = [
  "aws-lc-sys",
  "zeroize",
@@ -160,9 +160,9 @@ dependencies = [
 
 [[package]]
 name = "aws-lc-sys"
-version = "0.42.0"
+version = "0.44.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6d9ceb1da931507a12f4fccea479dccd00da1943e1b4ae72d8e502d707361444"
+checksum = "f09fae7be8bb3174e05c6afdb34199e6dc0c7c04ba9fa237b1967adfbde27483"
 dependencies = [
  "cc",
  "cmake",
@@ -194,9 +194,9 @@ checksum = "5e764a1d40d510daf35e07be9eb06e75770908c27d411ee6c92109c9840eaaf7"
 
 [[package]]
 name = "bitflags"
-version = "2.13.0"
+version = "2.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b4388bee8683e3d04af747c73422af53102d2bd24d9eadb6cbc100baef4b43f8"
+checksum = "b588b76d00fde79687d7646a9b5bdf3cc0f655e0bbd080335a95d7e96f3587da"
 
 [[package]]
 name = "block-buffer"
@@ -209,9 +209,9 @@ dependencies = [
 
 [[package]]
 name = "bstr"
-version = "1.12.3"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5cee35f73844aa3014bb606320a6c1f010249dbdf43342fe54b5a4f6a8ed4b79"
+checksum = "1f7dc094d718f2e1c1559ad110e27eeaae14a5465d3d56dd6dbd793079fbd530"
 dependencies = [
  "memchr",
  "regex-automata",
@@ -232,15 +232,15 @@ checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"
 
 [[package]]
 name = "bytes"
-version = "1.12.0"
+version = "1.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ae3f5d315924270530207e2a68396c3cc547f6dca3fbdca317cfb1a51edb593"
+checksum = "fc652a48c352aef3ea3aed32080501cf3ef6ed5da78602a020c991775b0aff04"
 
 [[package]]
 name = "cc"
-version = "1.2.66"
+version = "1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f5d6cac793997bd970000024b2934968efe83b382de4fdcf4fcb46b6ee4ad996"
+checksum = "5d262e149917187838d5b42777c8253bcb64500067342904e7d429499a6f277e"
 dependencies = [
  "find-msvc-tools",
  "jobserver",
@@ -262,9 +262,9 @@ checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "cfg_aliases"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"
+checksum = "f079e83a288787bcd14a6aea84cee5c87a67c5a3e660c30f557a3d24761b3527"
 
 [[package]]
 name = "chacha20"
@@ -288,9 +288,9 @@ dependencies = [
 
 [[package]]
 name = "clap"
-version = "4.6.1"
+version = "4.6.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ddb117e43bbf7dacf0a4190fef4d345b9bad68dfc649cb349e7d17d28428e51"
+checksum = "473c7e07f409a8d772161724aa8db6a765a2532a70f9667eeb7b49d3d02fbdca"
 dependencies = [
  "clap_builder",
  "clap_derive",
@@ -308,9 +308,9 @@ dependencies = [
 
 [[package]]
 name = "clap_builder"
-version = "4.6.0"
+version = "4.6.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "714a53001bf66416adb0e2ef5ac857140e7dc3a0c48fb28b2f10762fc4b5069f"
+checksum = "7b48fea5a88e9ae728a2dcbedbfc0e730f7d60da42e1cb049a83c9fb8b789889"
 dependencies = [
  "anstream",
  "anstyle",
@@ -321,23 +321,23 @@ dependencies = [
 
 [[package]]
 name = "clap_complete"
-version = "4.6.7"
+version = "4.6.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db8b397918185f0161ff3d6fcaa9e4bfc09b8367caf6e1d4a2848e5477ed027b"
+checksum = "3be2ad0423bdbbb0e25bc89add796f3559706d4a95e1bc98e4d9662a957b6a19"
 dependencies = [
  "clap",
 ]
 
 [[package]]
 name = "clap_derive"
-version = "4.6.1"
+version = "4.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2ce8604710f6733aa641a2b3731eaa1e8b3d9973d5e3565da11800813f997a9"
+checksum = "d012d2b9d65aca7f18f4d9878a045bc17899bba951561ba5ec3c2ba1eed9a061"
 dependencies = [
  "heck",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 3.0.3",
 ]
 
 [[package]]
@@ -442,9 +442,9 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-deque"
-version = "0.8.6"
+version = "0.8.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9dd111b7b7f7d55b72c0a6ae361660ee5853c9af73f70c3c2ef6858b950e2e51"
+checksum = "5181e0de7b61eb03a81e347d6dd8797bae9da5146707b51077e2d71a54ec0ceb"
 dependencies = [
  "crossbeam-epoch",
  "crossbeam-utils",
@@ -452,18 +452,18 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-epoch"
-version = "0.9.18"
+version = "0.9.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b82ac4a3c2ca9c3460964f020e1402edd5753411d7737aa39c3714ad1b5420e"
+checksum = "2d6914041f254d6e9176c01941b21115dcfb7089e55135a35411081bd106ef3f"
 dependencies = [
  "crossbeam-utils",
 ]
 
 [[package]]
 name = "crossbeam-utils"
-version = "0.8.21"
+version = "0.8.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
+checksum = "61803da095bee82a81bb1a452ecc25d3b2f1416d1897eb86430c6159ef717c17"
 
 [[package]]
 name = "crypto-common"
@@ -532,13 +532,13 @@ dependencies = [
 
 [[package]]
 name = "displaydoc"
-version = "0.2.6"
+version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ac70aa55017e108007fbaf5aa0f54b021c98f92ff8af59d42eda9da96e3dd4f"
+checksum = "c6232dd377dcc64799954cbd3a9bb882e9cdc1308ccd87b1c098f1fb2eaf82a8"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 3.0.3",
 ]
 
 [[package]]
@@ -562,9 +562,9 @@ dependencies = [
 
 [[package]]
 name = "either"
-version = "1.16.0"
+version = "1.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "91622ff5e7162018101f2fea40d6ebf4a78bbe5a49736a2020649edf9693679e"
+checksum = "9e5e8f6c15a24b9a3ee5efec809ccd006d3b30e8b3bb63c39af737c7f87daa1d"
 
 [[package]]
 name = "encode_unicode"
@@ -574,22 +574,22 @@ checksum = "34aa73646ffb006b8f5147f3dc182bd4bcb190227ce861fc4a4844bf8e3cb2c0"
 
 [[package]]
 name = "enum-map"
-version = "2.7.3"
+version = "3.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6866f3bfdf8207509a033af1a75a7b08abda06bbaaeae6669323fd5a097df2e9"
+checksum = "d4532960034c15ba2f55e9eee631040ecc473c32e6c4b200828c759840f13a06"
 dependencies = [
  "enum-map-derive",
 ]
 
 [[package]]
 name = "enum-map-derive"
-version = "0.17.0"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f282cfdfe92516eb26c2af8589c274c7c17681f5ecc03c18255fe741c6aa64eb"
+checksum = "7127272f64b3e098f7d81f350d672081b879bff896d219c42370dc858b1af9ff"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 3.0.3",
 ]
 
 [[package]]
@@ -630,9 +630,9 @@ dependencies = [
 
 [[package]]
 name = "fastrand"
-version = "2.4.1"
+version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9f1f227452a390804cdb637b74a86990f2a7d7ba4b7d5693aac9b4dd6defd8d6"
+checksum = "da7c62ceae207dd37ea5b845da6a0696c799f85e97da1ab5b7910be3c1c80223"
 
 [[package]]
 name = "filetime"
@@ -646,9 +646,9 @@ dependencies = [
 
 [[package]]
 name = "find-msvc-tools"
-version = "0.1.9"
+version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5baebc0774151f905a1a2cc41989300b1e6fbb29aff0ceffa1064fdd3088d582"
+checksum = "26b73573e6edcd2af0cdf47bd6cb58f0b3839491263c314eaad1ccf24430e1de"
 
 [[package]]
 name = "flate2"
@@ -713,9 +713,9 @@ checksum = "42703706b716c37f96a77aea830392ad231f44c9e9a67872fa5548707e11b11c"
 
 [[package]]
 name = "futures-channel"
-version = "0.3.32"
+version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "07bbe89c50d7a535e539b8c17bc0b49bdb77747034daa8087407d655f3f7cc1d"
+checksum = "262590f4fe6afeb0bc83be1daa64e52657fe185690a958af7f3ad0e92085c5ae"
 dependencies = [
  "futures-core",
  "futures-sink",
@@ -723,15 +723,15 @@ dependencies = [
 
 [[package]]
 name = "futures-core"
-version = "0.3.32"
+version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e3450815272ef58cec6d564423f6e755e25379b217b0bc688e295ba24df6b1d"
+checksum = "2cd50c473c80f6d7c3670a752354b8e569b1a7cbfdc0419ec88e5edad85e0dc7"
 
 [[package]]
 name = "futures-executor"
-version = "0.3.32"
+version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "baf29c38818342a3b26b5b923639e7b1f4a61fc5e76102d4b1981c6dc7a7579d"
+checksum = "6754879cc9f2c66f88c6e5c35344bb0bdb0708b0352b1201815667c7eabc7458"
 dependencies = [
  "futures-core",
  "futures-task",
@@ -740,38 +740,38 @@ dependencies = [
 
 [[package]]
 name = "futures-io"
-version = "0.3.32"
+version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cecba35d7ad927e23624b22ad55235f2239cfa44fd10428eecbeba6d6a717718"
+checksum = "4577ecaa3c4f96589d473f679a71b596316f6641bc350038b962a5daf0085d7a"
 
 [[package]]
 name = "futures-macro"
-version = "0.3.32"
+version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e835b70203e41293343137df5c0664546da5745f82ec9b84d40be8336958447b"
+checksum = "2d6d3cde68c518367be28956066ddfef33813991b77a55005a69dae04bf3b10b"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
 ]
 
 [[package]]
 name = "futures-sink"
-version = "0.3.32"
+version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c39754e157331b013978ec91992bde1ac089843443c49cbc7f46150b0fad0893"
+checksum = "e34418ac499d6305c2fb5ad0ed2f6ac998c5f8ca209b4510f7f94242c647e307"
 
 [[package]]
 name = "futures-task"
-version = "0.3.32"
+version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "037711b3d59c33004d3856fbdc83b99d4ff37a24768fa1be9ce3538a1cde4393"
+checksum = "b231ed28831efb4a61a08580c4bc233ec56bc009f4cd8f52da2c3cb97df0c109"
 
 [[package]]
 name = "futures-util"
-version = "0.3.32"
+version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "389ca41296e6190b48053de0321d02a77f32f8a5d2461dd38762c0593805c6d6"
+checksum = "a77a90a256fce34da66415271e30f94ee91c57b04b8a2c042d9cf3220179deaa"
 dependencies = [
  "futures-core",
  "futures-io",
@@ -836,7 +836,7 @@ dependencies = [
  "log",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
  "time",
 ]
 
@@ -907,15 +907,15 @@ dependencies = [
 
 [[package]]
 name = "html-escape"
-version = "0.2.14"
+version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46c1ff2d1cbf39efe5af0900ced8a069b5e61557a17544eb0c4a50239937389e"
+checksum = "c9356095b4b41197bba32173600e1582792cda618f65d12f68e2e77d273413c5"
 
 [[package]]
 name = "http"
-version = "1.4.2"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6970f50e31d6fc17d3fa27329444bfa74e196cf62e95052a3f6fee181dba6425"
+checksum = "918d3568bebf352712bc2ef3d46a8bcf1a75b373be6539de198e9105cbbf9ce0"
 dependencies = [
  "bytes",
  "itoa",
@@ -923,9 +923,9 @@ dependencies = [
 
 [[package]]
 name = "http-body"
-version = "1.0.1"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1efedce1fb8e6913f23e0c92de8e62cd5b772a67e7b3946df930a62566c93184"
+checksum = "ca2a8f2913ee65f60facd6a5905613afaa448497a0230cc41ce022d93290bc2c"
 dependencies = [
  "bytes",
  "http",
@@ -933,9 +933,9 @@ dependencies = [
 
 [[package]]
 name = "http-body-util"
-version = "0.1.3"
+version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b021d93e26becf5dc7e1b75b1bed1fd93124b374ceb73f43d4d4eafec896a64a"
+checksum = "e9f41fd6a08e4d4ec69df65976da761afd5ad5e58a9d4acb46bd1c953a9e3ff2"
 dependencies = [
  "bytes",
  "futures-core",
@@ -958,18 +958,18 @@ checksum = "df3b46402a9d5adb4c86a0cf463f42e19994e3ee891101b1841f30a545cb49a9"
 
 [[package]]
 name = "hybrid-array"
-version = "0.4.13"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "818356c5132c1fede50f837ca96afbe78ff42413047f4abb886217845e1b6c8c"
+checksum = "707114b52a152fa7bdb290cd7cd5912d9467273b6d74e21b8d81aca1f8533f6b"
 dependencies = [
  "typenum",
 ]
 
 [[package]]
 name = "hyper"
-version = "1.10.1"
+version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "55281c53a1894c864990125767da440a4e630446785086f52523b20033b74498"
+checksum = "d22053281f852e11534f5198498373cbb59295120a20771d90f7ed1897490a72"
 dependencies = [
  "atomic-waker",
  "bytes",
@@ -1182,9 +1182,9 @@ dependencies = [
 
 [[package]]
 name = "ipnet"
-version = "2.12.0"
+version = "2.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d98f6fed1fde3f8c21bc40a1abb88dd75e67924f9cffc3ef95607bad8017f8e2"
+checksum = "6a756c3fac73139e83f14c2d742155dd2b78d3ee56597b419a0579b7bdd6dd78"
 
 [[package]]
 name = "is_terminal_polyfill"
@@ -1228,7 +1228,7 @@ dependencies = [
  "jni-sys",
  "log",
  "simd_cesu8",
- "thiserror 2.0.18",
+ "thiserror 2.0.20",
  "walkdir",
  "windows-link",
 ]
@@ -1243,7 +1243,7 @@ dependencies = [
  "quote",
  "rustc_version",
  "simd_cesu8",
- "syn",
+ "syn 2.0.119",
 ]
 
 [[package]]
@@ -1262,24 +1262,24 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "38c0b942f458fe50cdac086d2f946512305e5631e720728f2a61aabcd47a6264"
 dependencies = [
  "quote",
- "syn",
+ "syn 2.0.119",
 ]
 
 [[package]]
 name = "jobserver"
-version = "0.1.34"
+version = "0.1.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9afb3de4395d6b3e67a780b6de64b51c978ecf11cb9a462c66be7d4ca9039d33"
+checksum = "1c00acbd29eabad4a2392fa0e921c874934dbbf4194312ad20f04a0ed67a3cb3"
 dependencies = [
- "getrandom 0.3.4",
+ "getrandom 0.4.3",
  "libc",
 ]
 
 [[package]]
 name = "js-sys"
-version = "0.3.103"
+version = "0.3.104"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "53b44bfcdb3f8d5837a46dae1ca9660a837176eee74a28b229bc626816589102"
+checksum = "0e0c1080212aad755ea003d18543e8768dd432c48819efd73a7bf1e39b7a5a3a"
 dependencies = [
  "cfg-if 1.0.4",
  "futures-util",
@@ -1294,9 +1294,9 @@ checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 
 [[package]]
 name = "libc"
-version = "0.2.186"
+version = "0.2.189"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "68ab91017fe16c622486840e4c83c9a37afeff978bd239b5293d61ece587de66"
+checksum = "3eaf3ede3fee6db1a4c2ee091bf8a8b4dccdc6d17f656fb07896ee72867612f2"
 
 [[package]]
 name = "libz-sys"
@@ -1350,9 +1350,9 @@ dependencies = [
 
 [[package]]
 name = "memchr"
-version = "2.8.2"
+version = "2.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "88904434abc2901f197fe8cc55f0445e7ded921dba5911dad2e2b39b48e663c4"
+checksum = "cf8baf1c55e62ffcace7a9f06f4bd9cd3f0c4beb022d3b367256b91b87513d98"
 
 [[package]]
 name = "miniz_oxide"
@@ -1366,9 +1366,9 @@ dependencies = [
 
 [[package]]
 name = "mio"
-version = "1.2.1"
+version = "1.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "02bd0af71c67b473010cbbc60715ee815645a4dc942899111f494b4b737d6fda"
+checksum = "30d65c71f1ce40ab09135ce117d742b9f8a19ff91a41a8b57ed50bc2de59c427"
 dependencies = [
  "libc",
  "wasi",
@@ -1498,7 +1498,7 @@ checksum = "a948666b637a0f465e8564c73e89d4dde00d72d4d473cc972f390fc3dcee7d9c"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
 ]
 
 [[package]]
@@ -1515,9 +1515,9 @@ checksum = "7c87def4c32ab89d880effc9e097653c8da5d6ef28e6b539d313baaacfbafcbe"
 
 [[package]]
 name = "openssl-src"
-version = "300.5.4+3.5.4"
+version = "300.6.1+3.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a507b3792995dae9b0df8a1c1e3771e8418b7c2d9f0baeba32e6fe8b06c7cb72"
+checksum = "46eb8fb9fb3b61ce1c0f8a026c4c1a0714d3a9e138e7fbde78753ce2babc3846"
 dependencies = [
  "cc",
 ]
@@ -1545,7 +1545,7 @@ dependencies = [
  "futures-sink",
  "js-sys",
  "pin-project-lite",
- "thiserror 2.0.18",
+ "thiserror 2.0.20",
  "tracing",
 ]
 
@@ -1575,7 +1575,7 @@ dependencies = [
  "opentelemetry_sdk",
  "prost",
  "reqwest",
- "thiserror 2.0.18",
+ "thiserror 2.0.20",
  "tokio",
  "tonic",
  "tonic-types",
@@ -1606,8 +1606,8 @@ dependencies = [
  "opentelemetry",
  "percent-encoding",
  "portable-atomic",
- "rand 0.9.4",
- "thiserror 2.0.18",
+ "rand 0.9.5",
+ "thiserror 2.0.20",
  "tokio",
  "tokio-stream",
 ]
@@ -1635,7 +1635,7 @@ checksum = "c96395f0a926bc13b1c17622aaddda1ecb55d49c8f1bf9777e4d877800a43f8b"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
 ]
 
 [[package]]
@@ -1652,15 +1652,15 @@ checksum = "19f132c84eca552bf34cab8ec81f1c1dcc229b811638f9d283dceabe58c5569e"
 
 [[package]]
 name = "platforms"
-version = "3.12.0"
+version = "4.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9245c6e7c5a6bcdd7977fdf6d1e1c67f4cc2d0d58c041df0ea5940953033e6ca"
+checksum = "acff5dfd42135d89cd7ad74a8c52813bbec91bf62c018ddd89390127767caab5"
 
 [[package]]
 name = "portable-atomic"
-version = "1.13.1"
+version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c33a9471896f1c69cecef8d20cbe2f7accd12527ce60845ff44c153bb2a21b49"
+checksum = "05c8b63e8d9609db387f0324918f81d68fe27748f084ef092fb35954d0539a85"
 
 [[package]]
 name = "potential_utf"
@@ -1688,9 +1688,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.106"
+version = "1.0.107"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
+checksum = "985e7ec9bb745e6ce6535b544d84d6cd6f7ad8bd711c398938ae983b91a766d9"
 dependencies = [
  "unicode-ident",
 ]
@@ -1705,7 +1705,7 @@ dependencies = [
  "bit-vec",
  "bitflags",
  "num-traits",
- "rand 0.9.4",
+ "rand 0.9.5",
  "rand_chacha",
  "rand_xorshift",
  "regex-syntax",
@@ -1734,7 +1734,7 @@ dependencies = [
  "itertools 0.14.0",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
 ]
 
 [[package]]
@@ -1765,9 +1765,9 @@ checksum = "a1d01941d82fa2ab50be1e79e6714289dd7cde78eba4c074bc5a4374f650dfe0"
 
 [[package]]
 name = "quote"
-version = "1.0.46"
+version = "1.0.47"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dfbc457d0c7a0759a614551b11a6409e5951f6c7537be1f1b7682b9ae9230368"
+checksum = "1fbf4db142a473a8d80c26bbf18454ed458bf8d26c8219c331daecfdbd079001"
 dependencies = [
  "proc-macro2",
 ]
@@ -1786,9 +1786,9 @@ checksum = "f8dcc9c7d52a811697d2151c701e0d08956f92b0e24136cf4cf27b57a6a0d9bf"
 
 [[package]]
 name = "rand"
-version = "0.9.4"
+version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "44c5af06bb1b7d3216d91932aed5265164bf384dc89cd6ba05cf59a35f5f76ea"
+checksum = "b9ef1d0d795eb7d84685bca4f72f3649f064e6641543d3a8c415898726a57b41"
 dependencies = [
  "rand_chacha",
  "rand_core 0.9.5",
@@ -1861,9 +1861,9 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.12.4"
+version = "1.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f1292b7759ae1cb9ec195452d1390a074f0cd8541ab7a5a8c31cd6db45d4a6ba"
+checksum = "f020237b6c8eed93db2e2cb53c00c60a8e1bc73da7d073199a1180401450218d"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -1873,9 +1873,9 @@ dependencies = [
 
 [[package]]
 name = "regex-automata"
-version = "0.4.14"
+version = "0.4.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e1dd4122fc1595e8162618945476892eefca7b88c52820e74af6262213cae8f"
+checksum = "ad8553b9b26413251cbf30e620595c7a41b3887f03da04579c0e6b0d6a06b4b2"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -1951,7 +1951,7 @@ version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1cab9bd343c737660e523ee69f788018f3db686d537d2fd0f99c9f747c1bda4f"
 dependencies = [
- "rand 0.9.4",
+ "rand 0.9.5",
 ]
 
 [[package]]
@@ -2002,9 +2002,9 @@ dependencies = [
 
 [[package]]
 name = "rustls"
-version = "0.23.41"
+version = "0.23.43"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6b92b125634d9b795e7beca796cc790df15a7fb38323bf3196fda83292d06b1f"
+checksum = "0283386ce02abc0151e1761d08802dfe86c173b0b494af5cbc086574e453da06"
 dependencies = [
  "aws-lc-rs",
  "log",
@@ -2029,9 +2029,9 @@ dependencies = [
 
 [[package]]
 name = "rustls-pki-types"
-version = "1.15.0"
+version = "1.15.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "764899a24af3980067ee14bc143654f297b22eaebfe3c7b6b211920a5a59b046"
+checksum = "2f4925028c7eb5d1fcdaf196971378ed9d2c1c4efc7dc5d011256f76c99c0a96"
 dependencies = [
  "zeroize",
 ]
@@ -2083,7 +2083,6 @@ dependencies = [
  "anstyle",
  "anyhow",
  "cc",
- "cfg-if 1.0.4",
  "chrono",
  "clap",
  "clap-cargo",
@@ -2108,7 +2107,6 @@ dependencies = [
  "libz-sys",
  "opener",
  "openssl",
- "openssl-src",
  "opentelemetry",
  "opentelemetry-otlp",
  "opentelemetry_sdk",
@@ -2135,7 +2133,7 @@ dependencies = [
  "strsim",
  "tar",
  "tempfile",
- "thiserror 2.0.18",
+ "thiserror 2.0.20",
  "threadpool",
  "tokio",
  "tokio-retry",
@@ -2159,9 +2157,9 @@ dependencies = [
 
 [[package]]
 name = "rustversion"
-version = "1.0.22"
+version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b39cdef0fa800fc44525c84ccb54a029961a8215f9619753635a9c0d2538d46d"
+checksum = "cf54715a573b99ac80df0bc206da022bcd442c974952c7b9720069370852e21f"
 
 [[package]]
 name = "rusty-fork"
@@ -2230,9 +2228,9 @@ checksum = "8a7852d02fc848982e0c167ef163aaff9cd91dc640ba85e263cb1ce46fae51cd"
 
 [[package]]
 name = "serde"
-version = "1.0.228"
+version = "1.0.229"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+checksum = "4148590afebada386688f18773da617792bf2ef03ffc1e4cbd2b1d45b023e0ba"
 dependencies = [
  "serde_core",
  "serde_derive",
@@ -2240,29 +2238,29 @@ dependencies = [
 
 [[package]]
 name = "serde_core"
-version = "1.0.228"
+version = "1.0.229"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
+checksum = "67dca2c9c51e58a4791a4b1ed58308b39c64224d349a935ab5039aa360942a48"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.228"
+version = "1.0.229"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
+checksum = "e7a5d71263a5a7d47b41f6b3f06ba276f10cc18b0931f1799f710578e2309348"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 3.0.3",
 ]
 
 [[package]]
 name = "serde_json"
-version = "1.0.150"
+version = "1.0.151"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e8014e44b4736ed0538adeecded0fce2a272f22dc9578a7eb6b2d9993c74cfb9"
+checksum = "c841b55ecdae098c80dcae9cf767f6f8a0c2cdb3416bbef72181df4d0fe73f14"
 dependencies = [
  "itoa",
  "memchr",
@@ -2308,15 +2306,15 @@ checksum = "f8fadd59c855ef2080decdef8ff161eb6661b86933c9d82e5ba29dc602a55aba"
 
 [[package]]
 name = "simd-adler32"
-version = "0.3.9"
+version = "0.3.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "703d5c7ef118737c72f1af64ad2f6f8c5e1921f818cdcb97b8fe6fc69bf66214"
+checksum = "3a219298ac11a56ea9a6d2120044824d6f01aeb034955e7af7bc16858527deea"
 
 [[package]]
 name = "simd_cesu8"
-version = "1.1.1"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "94f90157bb87cddf702797c5dadfa0be7d266cdf49e22da2fcaa32eff75b2c33"
+checksum = "11031e251abf8611c80f460e19dbdeb54a66db918e49c65a7065b46ac7aec520"
 dependencies = [
  "rustc_version",
  "simdutf8",
@@ -2330,9 +2328,9 @@ checksum = "e3a9fe34e3e7a50316060351f37187a3f546bce95496156754b601a5fa71b76e"
 
 [[package]]
 name = "similar"
-version = "3.1.1"
+version = "3.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6505efef05804732ed8a3f2d4f279429eb485bd69d5b0cc6b19cc02005cda16"
+checksum = "85ee016af5d736b69fc89e19254540fa4b5f5492853fb5503920f084011c78b6"
 dependencies = [
  "bstr",
 ]
@@ -2375,9 +2373,9 @@ dependencies = [
 
 [[package]]
 name = "socket2"
-version = "0.6.4"
+version = "0.6.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "52d1cfed4120b4d927bf7c0f86d2087a4a7d6027c906d9f9d525a80573b9be51"
+checksum = "c3d1e2c7f27f8d4cb10542a02c49005dbd6e93095799d6f3be745fae9f8fedd4"
 dependencies = [
  "libc",
  "windows-sys 0.61.2",
@@ -2403,9 +2401,20 @@ checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 
 [[package]]
 name = "syn"
-version = "2.0.118"
+version = "2.0.119"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "872831b642d1a07999a962a351ed35b955ea2cfc8f3862091e2a240a84f17297"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "syn"
+version = "3.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1b9ae57f904213ebb649ce6895b8a66c66f0203b9319718f69a5612a065b1422"
+checksum = "53e9bae58849f64dfa4f5d5ae372c8341f7305f82a3868709269343628b659a3"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2429,7 +2438,7 @@ checksum = "728a70f3dbaf5bab7f0c4b1ac8d7ae5ea60a4b5549c8a5914361c99147a709d2"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
 ]
 
 [[package]]
@@ -2487,11 +2496,11 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "2.0.18"
+version = "2.0.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4288b5bcbc7920c07a1149a35cf9590a2aa808e0bc1eafaade0b80947865fbc4"
+checksum = "ec86235f5fcc2a73650310756d2ac5b138a5780bbbdfae3eeccec992c435ba4f"
 dependencies = [
- "thiserror-impl 2.0.18",
+ "thiserror-impl 2.0.20",
 ]
 
 [[package]]
@@ -2502,25 +2511,25 @@ checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "2.0.18"
+version = "2.0.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ebc4ee7f67670e9b64d05fa4253e753e016c6c95ff35b89b7941d6b856dec1d5"
+checksum = "bc04cd3e1236dd4a98afca4569f2deb3f120e5422a4023be2cb683f8486292af"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 3.0.3",
 ]
 
 [[package]]
 name = "thread_local"
-version = "1.1.9"
+version = "1.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f60246a4944f24f6e018aa17cdeffb7818b76356965d03b07d6a9886e8962185"
+checksum = "1ad99c4c6d32803332c548b1af0540b357b3f5fc0be8f6c6bfe8b2e6ae784070"
 dependencies = [
  "cfg-if 1.0.4",
 ]
@@ -2536,9 +2545,9 @@ dependencies = [
 
 [[package]]
 name = "time"
-version = "0.3.53"
+version = "0.3.55"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18dfaaeddcb932337b5e7866ee7d0ce9b76d2fd092997146f187ec09b4558a50"
+checksum = "cdb87b95ec50ddfa440816d227a17b2ccbdda963a316a727fda0fc4334f7d134"
 dependencies = [
  "deranged",
  "num-conv",
@@ -2556,9 +2565,9 @@ checksum = "9e1c906769ad99c88eaa54e728060edef082f8e358ff32030cb7c7d315e81109"
 
 [[package]]
 name = "time-macros"
-version = "0.2.31"
+version = "0.2.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c431b87111666e491a90baa837f914fb45cd5dc3c268591b0220ff5057f2085f"
+checksum = "7e689342a48d2ea927c87ea50cabf8594854bf940e9310208848d680d668ed85"
 dependencies = [
  "num-conv",
  "time-core",
@@ -2576,9 +2585,9 @@ dependencies = [
 
 [[package]]
 name = "tokio"
-version = "1.52.3"
+version = "1.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8fc7f01b389ac15039e4dc9531aa973a135d7a4135281b12d7c1bc79fd57fffe"
+checksum = "202caea871b69668250d242070849eb495be178ed697a3e98aebce5bc81a0bed"
 dependencies = [
  "bytes",
  "libc",
@@ -2591,13 +2600,13 @@ dependencies = [
 
 [[package]]
 name = "tokio-macros"
-version = "2.7.0"
+version = "2.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "385a6cb71ab9ab790c5fe8d67f1645e6c450a7ce006a33de03daa956cf70a496"
+checksum = "78773a2a397f451582ce068015985c33193cf6dea8b74d2a639fe457b2f07b0e"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 3.0.3",
 ]
 
 [[package]]
@@ -2633,9 +2642,9 @@ dependencies = [
 
 [[package]]
 name = "tokio-stream"
-version = "0.1.18"
+version = "0.1.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32da49809aab5c3bc678af03902d4ccddea2a87d028d86392a4b1560c6906c70"
+checksum = "a3d06f0b082ba57c26b79407372e57cf2a1e28124f78e9479fe80322cf53420b"
 dependencies = [
  "futures-core",
  "pin-project-lite",
@@ -2644,22 +2653,23 @@ dependencies = [
 
 [[package]]
 name = "tokio-util"
-version = "0.7.18"
+version = "0.7.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ae9cec805b01e8fc3fd2fe289f89149a9b66dd16786abd8b19cfa7b48cb0098"
+checksum = "494815d09bf52b5548659851081238f0ca39ff638363907596da739561c62c52"
 dependencies = [
  "bytes",
  "futures-core",
  "futures-sink",
+ "libc",
  "pin-project-lite",
  "tokio",
 ]
 
 [[package]]
 name = "toml"
-version = "1.1.2+spec-1.1.0"
+version = "1.1.4+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "81f3d15e84cbcd896376e6730314d59fb5a87f31e4b038454184435cd57defee"
+checksum = "3aace63f4bbcdfc2c965b059de67119c89c4017a70d633be6c104910f67056f5"
 dependencies = [
  "indexmap",
  "serde_core",
@@ -2681,18 +2691,18 @@ dependencies = [
 
 [[package]]
 name = "toml_parser"
-version = "1.1.2+spec-1.1.0"
+version = "1.1.3+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a2abe9b86193656635d2411dc43050282ca48aa31c2451210f4202550afb7526"
+checksum = "1d38ac1cf9b95face32296c0a3ede1fdc270627c9d9c02a7274dd6d960dc4d56"
 dependencies = [
  "winnow",
 ]
 
 [[package]]
 name = "toml_writer"
-version = "1.1.1+spec-1.1.0"
+version = "1.1.2+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "756daf9b1013ebe47a8776667b466417e2d4c5679d441c26230efd9ef78692db"
+checksum = "7d56353a2a665ad0f41a421187180aab746c8c325620617ad883a99a1cbe66d2"
 
 [[package]]
 name = "tonic"
@@ -2815,7 +2825,7 @@ checksum = "7490cfa5ec963746568740651ac6781f701c9c5ea257c58e057f3ba8cf69e8da"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
 ]
 
 [[package]]
@@ -3002,9 +3012,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.126"
+version = "0.2.127"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b067c0c11094aef6b7a801c1e34a26affafdf3d051dba08456b868789aaf9a4"
+checksum = "1b70935747edd64d89de3efa29d73789b806c15798f8e7dca4d8ac356b50ce70"
 dependencies = [
  "cfg-if 1.0.4",
  "once_cell",
@@ -3015,9 +3025,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-futures"
-version = "0.4.76"
+version = "0.4.77"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c62df1340f32221cb9c54d6a27b030e3dba64361d4a95bed55f9aacb44da291d"
+checksum = "6b7777d5cc23d0e91404e53ce2d5e8ec7acae3026b16233dba62cd3246457950"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -3025,9 +3035,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.126"
+version = "0.2.127"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "167ce5e579f6bcf889c4f7175a8a5a585de84e8ff93976ce393efa5f2837aab1"
+checksum = "77775f8f3f7217702089053b94958f8f54061a3f663417df76e19cbdcca29bc1"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -3035,22 +3045,22 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.126"
+version = "0.2.127"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f3997c7839262f4ef12cf90b818d6340c18e80f263f1a94bf157d0ec4420380e"
+checksum = "e11d33f857dc2fb11b8bc75aee111aa9cbeb12cd9f25efd3d4c2a3dd4e235284"
 dependencies = [
  "bumpalo",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.126"
+version = "0.2.127"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc1b4cb0cc549fcf58d7dfc081778139b3d283a081644e833e84682ad71cea24"
+checksum = "7ef64dbcc55df09c7e5a46182d181c2cfa3e925f3da937ea764728b4bbb9dcbf"
 dependencies = [
  "unicode-ident",
 ]
@@ -3070,9 +3080,9 @@ dependencies = [
 
 [[package]]
 name = "web-sys"
-version = "0.3.103"
+version = "0.3.104"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8622dcb61c0bcc9fffa6938bed81210af2da9a7e4a1a834b2e37a59b6dfb6141"
+checksum = "c435338968042f4f59a557f690a253676d47ce13ceb55d70100e7facf6620a30"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -3090,9 +3100,9 @@ dependencies = [
 
 [[package]]
 name = "webpki-root-certs"
-version = "1.0.8"
+version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d46a5a140e6f7afeccd8eae97eff335163939eac8b929834875168b29b3d267"
+checksum = "b96554aa2acc8ccdb7e1c9a58a7a68dd5d13bccc69cd124cb09406db612a1c9b"
 dependencies = [
  "rustls-pki-types",
 ]
@@ -3256,9 +3266,9 @@ checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
 
 [[package]]
 name = "winnow"
-version = "1.0.3"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0592e1c9d151f854e6fd382574c3a0855250e1d9b2f99d9281c6e6391af352f1"
+checksum = "23b97319f7b8343df12cc98938e5c3eb436064524c8d2b4e30a1d3a36eecdf81"
 
 [[package]]
 name = "wit-bindgen"
@@ -3310,28 +3320,28 @@ checksum = "de844c262c8848816172cef550288e7dc6c7b7814b4ee56b3e1553f275f1858e"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
  "synstructure",
 ]
 
 [[package]]
 name = "zerocopy"
-version = "0.8.52"
+version = "0.8.56"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce1022995ff5ff5d841ad7d994facc23098cd40152f2c1d11cd607c6f530653f"
+checksum = "556764e583adb45a9f8d413c2a147fa7e8d821e48e12b14fd560b607998b75eb"
 dependencies = [
  "zerocopy-derive",
 ]
 
 [[package]]
 name = "zerocopy-derive"
-version = "0.8.52"
+version = "0.8.56"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ae7f38b72ec2a254e2b87ef277cf2cd4fb97cbebf944faa6f33354da0867930"
+checksum = "f2ab42fc20575779bd240faa45f94a74256f755c0fa9e89f0ede20d91d0cdfc1"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
 ]
 
 [[package]]
@@ -3351,7 +3361,7 @@ checksum = "11532158c46691caf0f2593ea8358fed6bbf68a0315e80aae9bd41fbade684a1"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
  "synstructure",
 ]
 
@@ -3391,20 +3401,20 @@ checksum = "625dc425cab0dca6dc3c3319506e6593dcb08a9f387ea3b284dbd52a92c40555"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.119",
 ]
 
 [[package]]
 name = "zlib-rs"
-version = "0.6.5"
+version = "0.6.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5431d5661c32445236631278f27946e444ddafe4684cac70b185272d4f9c52d5"
+checksum = "34b31d188d9d685a4f9c7b46d6e36631b07058d2cfe190267adce54dc230bf12"
 
 [[package]]
 name = "zmij"
-version = "1.0.21"
+version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b8848ee67ecc8aedbaf3e4122217aff892639231befc6a1b58d29fff4c2cabaa"
+checksum = "29666d0abbfad1e3dc4dcf6144730dd3a3ab225bbbdac83319345b1b44ccfc1b"
 
 [[package]]
 name = "zstd"
diff --git a/Cargo.toml b/Cargo.toml
index 2110cb28d8..069ba4a801 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -45,7 +45,6 @@ anstream = "1"
 anstyle = "1.0.11"
 anyhow = "1.0.69"
 cc = "1"
-cfg-if = "1.0"
 chrono = { version = "0.4", default-features = false, features = ["std"] }
 clap = { version = "4", features = ["derive", "wrap_help", "string"] }
 clap-cargo = "0.18.3"
@@ -53,7 +52,7 @@ clap_complete = "4"
 console = "0.16"
 curl = { version = "0.4.44", optional = true }
 effective-limits = "0.5.5"
-enum-map = "2.5.0"
+enum-map = "3.0.0"
 env_proxy = { version = "0.4.1", optional = true }
 faster-hex = "0.10.0"
 flate2 = { version = "1.1.1", default-features = false, features = ["zlib-rs"] }
@@ -61,6 +60,9 @@ fs_at = "0.2.1"
 futures-util = "0.3.31"
 git-testament = "0.2"
 home = "0.5.4"
+http-body-util = "0.1.0"
+hyper = { version = "1.0", default-features = false, features = ["server", "http1"] }
+hyper-util = { version = "0.1.1", features = ["tokio"] }
 indicatif = "0.18"
 itertools = "0.15"
 libc = "0.2"
@@ -68,13 +70,10 @@ opener = "0.8.0"
 # `openssl` is used by `curl` or `reqwest` backend although it isn't imported by rustup: this
 # allows controlling the vendoring status without exposing the presence of the download crate.
 openssl = { version = "0.10", optional = true }
-# HACK: Temporarily pinned due to ppc64 ELFv1/v2 ABI issue in 300.5.5, to be
-# removed when <https://github.com/openssl/openssl/issues/29815> lands.
-openssl-src = { version = "=300.5.4", optional = true }
 opentelemetry = { version = "0.32", optional = true }
 opentelemetry-otlp = { version = "0.32", features = ["grpc-tonic"], optional = true }
 opentelemetry_sdk = { version = "0.32", features = ["rt-tokio"], optional = true }
-platforms = "3.4"
+platforms = "4"
 pulldown-cmark = { version = "0.13", default-features = false }
 rand = "0.10"
 rayon = "1.10.0"
@@ -145,17 +144,14 @@ version = "0.61"
 libz-sys = "=1.1.24"
 
 [dev-dependencies]
-enum-map = "2.5.0"
-http-body-util = "0.1.0"
-hyper = { version = "1.0", default-features = false, features = ["server", "http1"] }
-hyper-util = { version = "0.1.1", features = ["tokio"] }
+enum-map = "3.0.0"
 proptest = "1.1.0"
 rustls-webpki = { version = "0.103.3" }
 tokio-rustls = "0.26.4"
 webpki-root-certs = "1"
 
 [build-dependencies]
-platforms = "3.4"
+platforms = "4"
 
 [lints.rust]
 rust_2018_idioms = { level = "deny", priority = -1 }
diff --git a/ci/actions-templates/linux-builds-template.yaml b/ci/actions-templates/linux-builds-template.yaml
index 214d666fab..cf6730e66a 100644
--- a/ci/actions-templates/linux-builds-template.yaml
+++ b/ci/actions-templates/linux-builds-template.yaml
@@ -44,6 +44,7 @@ jobs: # skip-main skip-pr skip-stable
           - armv7-linux-androideabi        # skip-pr skip-main
           - x86_64-linux-android           # skip-pr skip-main
           - riscv64gc-unknown-linux-gnu    # skip-pr skip-main
+          - riscv64gc-unknown-linux-musl   # skip-pr skip-main
           - loongarch64-unknown-linux-gnu  # skip-pr skip-main
           - loongarch64-unknown-linux-musl # skip-pr skip-main
         include:
@@ -187,13 +188,13 @@ jobs: # skip-main skip-pr skip-stable
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           AWS_DEFAULT_REGION: us-west-1
       - name: Configure AWS credentials
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         uses: aws-actions/configure-aws-credentials@v6
         with:
           role-to-assume: arn:aws:iam::890664054962:role/ci--rust-lang--rustup
           aws-region: us-east-1
       - name: Deploy build to rustup-builds bucket for release team
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         run: |
           aws --debug s3 cp --recursive deploy/ s3://rustup-builds/${{ github.sha }}
         env:
diff --git a/ci/actions-templates/macos-builds-template.yaml b/ci/actions-templates/macos-builds-template.yaml
index f7738b8ba0..f6411a929b 100644
--- a/ci/actions-templates/macos-builds-template.yaml
+++ b/ci/actions-templates/macos-builds-template.yaml
@@ -115,13 +115,13 @@ jobs: # skip-x86_64 skip-aarch64
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           AWS_DEFAULT_REGION: us-west-1
       - name: Configure AWS credentials
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         uses: aws-actions/configure-aws-credentials@v6
         with:
           role-to-assume: arn:aws:iam::890664054962:role/ci--rust-lang--rustup
           aws-region: us-east-1
       - name: Deploy build to rustup-builds bucket for release team
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         run: |
           aws --debug s3 cp --recursive deploy/ s3://rustup-builds/${{ github.sha }}
         env:
diff --git a/ci/actions-templates/windows-builds-template.yaml b/ci/actions-templates/windows-builds-template.yaml
index 60eed06a08..938dd01e12 100644
--- a/ci/actions-templates/windows-builds-template.yaml
+++ b/ci/actions-templates/windows-builds-template.yaml
@@ -193,13 +193,13 @@ jobs: # skip-main skip-pr skip-stable
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           AWS_DEFAULT_REGION: us-west-1
       - name: Configure AWS credentials
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         uses: aws-actions/configure-aws-credentials@v6
         with:
           role-to-assume: arn:aws:iam::890664054962:role/ci--rust-lang--rustup
           aws-region: us-east-1
       - name: Deploy build to rustup-builds bucket for release team
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && matrix.mode == 'release'
+        if: github.event_name == 'push' && matrix.mode == 'release' && (github.ref == 'refs/heads/stable' || github.ref == 'refs/heads/main')
         run: |
           aws --debug s3 cp --recursive dist s3://rustup-builds/${{ github.sha }}/dist
         env:
diff --git a/ci/cloudfront-invalidation.txt b/ci/cloudfront-invalidation.txt
index 9b86ac321c..ae1892448d 100644
--- a/ci/cloudfront-invalidation.txt
+++ b/ci/cloudfront-invalidation.txt
@@ -57,6 +57,10 @@ rustup/dist/powerpc64le-unknown-linux-gnu/rustup-init
 rustup/dist/powerpc64le-unknown-linux-gnu/rustup-init.sha256
 rustup/dist/powerpc64le-unknown-linux-musl/rustup-init
 rustup/dist/powerpc64le-unknown-linux-musl/rustup-init.sha256
+rustup/dist/riscv64gc-unknown-linux-gnu/rustup-init
+rustup/dist/riscv64gc-unknown-linux-gnu/rustup-init.sha256
+rustup/dist/riscv64gc-unknown-linux-musl/rustup-init
+rustup/dist/riscv64gc-unknown-linux-musl/rustup-init.sha256
 rustup/dist/s390x-unknown-linux-gnu/rustup-init
 rustup/dist/s390x-unknown-linux-gnu/rustup-init.sha256
 rustup/dist/sparcv9-sun-solaris/rustup-init.exe
diff --git a/ci/docker/riscv64gc-unknown-linux-musl/Dockerfile b/ci/docker/riscv64gc-unknown-linux-musl/Dockerfile
new file mode 100644
index 0000000000..3219088f87
--- /dev/null
+++ b/ci/docker/riscv64gc-unknown-linux-musl/Dockerfile
@@ -0,0 +1,8 @@
+FROM rust-riscv64gc-unknown-linux-musl
+
+# Building `aws-lc-rs` for Linux depends on `gcc-multilib`, `libclang` and `bindgen`.
+# See: https://aws.github.io/aws-lc-rs/requirements/linux
+RUN apt-get update && apt-get install -qy gcc-multilib libclang-dev
+
+ENV CC_riscv64gc_unknown_linux_musl=riscv64-unknown-linux-musl-gcc \
+    CARGO_TARGET_RISCV64GC_UNKNOWN_LINUX_MUSL_LINKER=riscv64-unknown-linux-musl-gcc
diff --git a/ci/fetch-rust-docker.bash b/ci/fetch-rust-docker.bash
index eb2f69f8e4..3a1c022309 100644
--- a/ci/fetch-rust-docker.bash
+++ b/ci/fetch-rust-docker.bash
@@ -45,7 +45,8 @@ case "$TARGET" in
   x86_64-unknown-illumos)          image=dist-x86_64-illumos ;;
   x86_64-unknown-linux-gnu)        image=dist-x86_64-linux ;;
   x86_64-unknown-netbsd)           image=dist-x86_64-netbsd ;;
-  riscv64gc-unknown-linux-gnu)     image=dist-riscv64-linux ;;
+  riscv64gc-unknown-linux-gnu)     image=dist-riscv64-linux-gnu ;;
+  riscv64gc-unknown-linux-musl)    image=dist-riscv64-linux-musl ;;
   loongarch64-unknown-linux-gnu)   image=dist-loongarch64-linux ;;
   loongarch64-unknown-linux-musl)  image=dist-loongarch64-musl ;;
   *) exit ;;
diff --git a/ci/run.bash b/ci/run.bash
index f9d28cd6e6..e7e61acc6b 100644
--- a/ci/run.bash
+++ b/ci/run.bash
@@ -20,10 +20,16 @@ if [ -n "$INSTALL_BINDGEN" ]; then
 fi
 
 
-FEATURES=('--no-default-features' '--features' 'curl-backend,reqwest-native-tls')
-case "$(uname -s)" in
-  *NT* ) ;; # Windows NT
-  * ) FEATURES+=('--features' 'vendored-openssl') ;;
+FEATURES=('--no-default-features')
+case "$TARGET" in
+  *-linux-android*) ;;
+  *)
+    FEATURES+=('--features' 'curl-backend,reqwest-native-tls')
+    case "$(uname -s)" in
+      *NT* ) ;; # Windows NT
+      * ) FEATURES+=('--features' 'vendored-openssl') ;;
+    esac
+    ;;
 esac
 
 case "$TARGET" in
diff --git a/doc/dev-guide/src/SUMMARY.md b/doc/dev-guide/src/SUMMARY.md
index 15e9b2b4b1..d95e347b52 100644
--- a/doc/dev-guide/src/SUMMARY.md
+++ b/doc/dev-guide/src/SUMMARY.md
@@ -1,9 +1,10 @@
 # Summary
 
 - [Introduction](index.md)
-    - [Linting](linting.md)
+  - [Linting](linting.md)
 - [Coding standards](coding-standards.md)
 - [Version numbers](version-numbers.md)
+- [Recipes](recipes.md)
 - [Release process](release-process.md)
 - [Tips and tricks](tips-and-tricks.md)
-- [Tracing](tracing.md)
\ No newline at end of file
+- [Tracing](tracing.md)
diff --git a/doc/dev-guide/src/index.md b/doc/dev-guide/src/index.md
index 0541d4e8f5..3bd36e4faa 100644
--- a/doc/dev-guide/src/index.md
+++ b/doc/dev-guide/src/index.md
@@ -48,3 +48,32 @@ Unless you explicitly state otherwise, any contribution intentionally
 submitted for inclusion in the work by you, as defined in the
 Apache-2.0 license, shall be dual licensed as in the README, without any
 additional terms or conditions.
+
+## AI policy
+
+Using AI (LLMs) as tools for coding is welcome. A high bar is held for all contributions to this
+project. Moreover, the project maintainers remain responsible for any code that is published as
+part of a release. Contributors are expected to be responsible for any code they publish.
+
+AI should not be used to generate comments when communicating with maintainers. Comments are
+expected to be written by humans. Comments that are believed to be written by AI may be hidden
+without notice.
+
+If you are opening an issue, you should be able to describe the problem in your own words.
+
+If you are opening a pull request, you are expected to be able to explain the proposed changes in
+your own words. This includes the pull request body and responses to questions. Make sure you have
+reviewed the PR yourself before submitting it for review to the maintainers. Do not copy responses
+from the AI when replying to questions from maintainers. As an exception, issues marked as `E-easy`
+are meant for new contributors as a learning opportunity; the use of an LLM when submitting PR for
+such issues is disallowed except without explicit permission from the team. Failure to comply may
+result in the PR being closed directly without further notice.
+
+If you wish to include context from an interaction with AI in your comments, it must be in a
+quote block (using `>`) and disclosed as such. It must be accompanied by human commentary
+explaining the relevance and implications of the context. Do not share long snippets.
+
+AI is useful when communicating as a non-native English speaker. If you are using AI to edit your
+comments for this purpose, please take the time to ensure it reflects your own voice and ideas.
+When using AI for translation, we recommend writing in your native language and including the AI
+translation in a quote block.
diff --git a/doc/dev-guide/src/recipes.md b/doc/dev-guide/src/recipes.md
new file mode 100644
index 0000000000..7feebf3577
--- /dev/null
+++ b/doc/dev-guide/src/recipes.md
@@ -0,0 +1,56 @@
+# Recipes
+
+This section contains some recipes for common tasks that you may want to
+perform when contributing to rustup.
+
+## Supporting a new tier 2 target with host tools
+
+In principle, all target tuples **with host tools** should be recognized by
+rustup and have its official rustup builds. Thus, once a new target has been
+promoted to tier 2 with host tools, it should also be explicitly supported by
+rustup through the following steps:
+
+1. Informing rustup of the new target:
+
+   At the moment of writing, GitHub Actions' runners natively support Linux,
+   Windows, and macOS. Tier 2 builds are mostly cross-compiled from Linux
+   (except for Windows and macOS targets, which are directly compiled from the
+   target platform), and thus we will be focusing on the Linux case below.
+
+   You can refer to [rustup#4688] for a practical example for adding a new tier
+   2 target via cross-builds from Linux, where you can find nearly all places
+   where you would need to mention your new target in the rustup codebase.
+
+   Notably, you would need to add a line in
+   `ci/actions-templates/linux-builds-template.yaml` to include it in rustup's
+   CI, while disabling the build for this target in all scenarios. At the
+   moment of writing, this is done by appending the YAML comment
+   `# skip-pr skip-master skip-stable`
+   at the end of the line when mentioning your target in that file.
+
+   On the other hand, if you need to support new Windows or macOS targets,
+   please don't hesitate to discuss this with the team in a dedicated [rustup
+   issue].
+
+   [rustup#4688]: https://github.com/rust-lang/rustup/pull/4688
+   [rustup issue]: https://github.com/rust-lang/rustup/issues
+
+2. Stabilizing the target:
+
+   When your new target reaches stable Rust, you can then enable the target in
+   certain CI scenarios, depending on the popularity of the target. At the
+   moment of writing, this is done by removing certain occurrences of `skip-*`
+   in the aforementioned YAML comment. In most cases, you would only need to
+   enable the target for the `stable` CI scenario by removing `skip-stable`.
+
+   You can refer to [rustup#4816] for a practical example for this step.
+
+   Do note that when creating the PR for this step, you will need to prove that
+   the target's CI is indeed working by removing `skip-pr` in a separate commit
+   to temporarily enable this target in this PR's CI. Once the CI is green, you
+   can send the link ([example][send-link]) to that CI run in the PR thread for
+   verification. After that, you can safely drop the temporary commit to get
+   the PR ready for merging.
+
+   [rustup#4816]: https://github.com/rust-lang/rustup/pull/4816
+   [send-link]: https://github.com/rust-lang/rustup/pull/4816#issuecomment-4263419604
diff --git a/doc/dev-guide/src/tracing.md b/doc/dev-guide/src/tracing.md
index 75caca1efc..ed3ffe2b75 100644
--- a/doc/dev-guide/src/tracing.md
+++ b/doc/dev-guide/src/tracing.md
@@ -59,7 +59,7 @@ receive log lines only from `rustup` itself with a max verbosity of `DEBUG`.
 ## Opentelemetry tracing
 
 The feature `otel` can be used when building rustup to turn on Opentelemetry
-tracing with an OLTP GRPC exporter.
+tracing with an OTLP gRPC exporter.
 
 This can be very useful for diagnosing performance or correctness issues in more
 complicated scenarios.
@@ -118,6 +118,6 @@ Some good general heuristics:
   as these tend to help figure the puzzle of what-is-happening
 - Default to not instrumenting thin shim functions (or at least, only instrument
   them temporarily while figuring out the shape of a problem)
-- Be way of debug build timing - release optimisations make a huge difference,
+- Be wary of debug build timing - release optimisations make a huge difference,
   though debug is a lot faster to iterate on. If something isn't a problem in
   release don't pay it too much heed in debug.
diff --git a/doc/user-guide/src/concepts/components.md b/doc/user-guide/src/concepts/components.md
index 2d9b74beeb..9dce622a9c 100644
--- a/doc/user-guide/src/concepts/components.md
+++ b/doc/user-guide/src/concepts/components.md
@@ -62,6 +62,8 @@ toolchains. The following is an overview of the different components:
 * `rustc-dev` --- This component contains the compiler as a library. Most users
   will not need this; it is only needed for development *of* tools that link
   to the compiler, such as making modifications to [Clippy].
+* `enzyme` --- This component enables the `std::autodiff` module in nightly Rust.
+  See [autodiff][enzyme] for more detail.
 
 ### Previous components
 
@@ -101,3 +103,4 @@ details.
 [rustup components history]: https://rust-lang.github.io/rustup-components-history/
 [profiles]: profiles.md
 [nightly availability]: channels.md#nightly-availability
+[enzyme]: https://rustc-dev-guide.rust-lang.org/autodiff/installation.html
diff --git a/doc/user-guide/src/installation/other.md b/doc/user-guide/src/installation/other.md
index 22ac13df73..fc9b918378 100644
--- a/doc/user-guide/src/installation/other.md
+++ b/doc/user-guide/src/installation/other.md
@@ -163,6 +163,10 @@ You can manually download `rustup-init` for a given target from
   - [sha256 file](https://static.rust-lang.org/rustup/dist/powerpc64le-unknown-linux-gnu/rustup-init.sha256)
 - [powerpc64le-unknown-linux-musl](https://static.rust-lang.org/rustup/dist/powerpc64le-unknown-linux-musl/rustup-init)
   - [sha256 file](https://static.rust-lang.org/rustup/dist/powerpc64le-unknown-linux-musl/rustup-init.sha256)
+- [riscv64gc-unknown-linux-gnu](https://static.rust-lang.org/rustup/dist/riscv64gc-unknown-linux-gnu/rustup-init)
+  - [sha256 file](https://static.rust-lang.org/rustup/dist/riscv64gc-unknown-linux-gnu/rustup-init.sha256)
+- [riscv64gc-unknown-linux-musl](https://static.rust-lang.org/rustup/dist/riscv64gc-unknown-linux-musl/rustup-init)
+  - [sha256 file](https://static.rust-lang.org/rustup/dist/riscv64gc-unknown-linux-musl/rustup-init.sha256)
 - [s390x-unknown-linux-gnu](https://static.rust-lang.org/rustup/dist/s390x-unknown-linux-gnu/rustup-init)
   - [sha256 file](https://static.rust-lang.org/rustup/dist/s390x-unknown-linux-gnu/rustup-init.sha256)
 - [sparcv9-sun-solaris](https://static.rust-lang.org/rustup/dist/sparcv9-sun-solaris/rustup-init)
diff --git a/doc/user-guide/src/installation/windows.md b/doc/user-guide/src/installation/windows.md
index 59ac3bde82..b9d5d52c40 100644
--- a/doc/user-guide/src/installation/windows.md
+++ b/doc/user-guide/src/installation/windows.md
@@ -25,13 +25,7 @@ target that tuple by default.
 You can change this behavior with `rustup set default-host` or during
 installation.
 
-For example, to explicitly select the 32-bit MSVC host:
-
-```console
-$ rustup set default-host i686-pc-windows-msvc
-```
-
-Or to choose the 64 bit GNU toolchain:
+For example, to choose the 64 bit GNU toolchain:
 
 ```console
 $ rustup set default-host x86_64-pc-windows-gnu
diff --git a/src/bin/rustup-init.rs b/src/bin/rustup-init.rs
index e844ddc19e..a0d408abc8 100644
--- a/src/bin/rustup-init.rs
+++ b/src/bin/rustup-init.rs
@@ -16,7 +16,6 @@
 use std::process::ExitCode;
 
 use anyhow::{Context, Result, anyhow};
-use cfg_if::cfg_if;
 // Public macros require availability of the internal symbols
 use rs_tracing::{
     close_trace_file, close_trace_file_internal, open_trace_file, trace_to_file_internal,
@@ -105,12 +104,9 @@ async fn run_rustup_inner(
         Some(n) if n.starts_with("rustup-gc-") => {
             // This is the final uninstallation stage on windows where
             // rustup deletes its own exe
-            cfg_if! {
-                if #[cfg(windows)] {
-                    self_update::complete_windows_uninstall(process)
-                } else {
-                    unreachable!("Attempted to use Windows-specific code on a non-Windows platform. Aborting.")
-                }
+            cfg_select! {
+                windows => self_update::complete_windows_uninstall(process),
+                _ => unreachable!("Attempted to use Windows-specific code on a non-Windows platform. Aborting."),
             }
         }
         Some(n) => {
diff --git a/src/cli.rs b/src/cli.rs
index 88a7586ce2..31807fa261 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -2,6 +2,7 @@
 #[macro_use]
 pub mod log;
 pub mod common;
+mod docs;
 pub mod errors;
 mod help;
 mod job;
diff --git a/src/cli/common.rs b/src/cli/common.rs
index 8ec17a13ec..e9d9ccd26f 100644
--- a/src/cli/common.rs
+++ b/src/cli/common.rs
@@ -25,7 +25,9 @@ use crate::{
     utils::{self, ExitCode},
 };
 
-pub(crate) const WARN_COMPLETE_PROFILE: &str = "downloading with complete profile isn't recommended unless you are a developer of the rust language";
+pub(crate) const WARN_COMPLETE_PROFILE: &str = "\
+downloading with the `complete` profile is deprecated
+help: consider switching to the `default` profile with `rustup set profile default`";
 
 pub(crate) fn confirm(question: &str, default: bool, process: &Process) -> Result<bool> {
     write!(process.stdout().lock(), "{question} ")?;
@@ -173,7 +175,7 @@ fn show_channel_updates(
                 // this is a bit strange: we don't supply the version we
                 // presumably had (for Installed and Unchanged), so we query it
                 // again. Perhaps we can do better.
-                let version = match Toolchain::new(cfg, name.into()) {
+                let version = match Toolchain::new(cfg, name.clone().into()) {
                     Ok(t) => t.rustc_version(),
                     Err(_) => String::from("(toolchain not installed)"),
                 };
diff --git a/src/cli/docs.rs b/src/cli/docs.rs
new file mode 100644
index 0000000000..081fe768bd
--- /dev/null
+++ b/src/cli/docs.rs
@@ -0,0 +1,369 @@
+//! `rustup doc` and `rustup man`: opening toolchain documentation and man pages.
+//!
+//! `rustup doc --serve` serves the documentation over a local HTTP server
+//! instead of opening it directly as a `file://` URL. Some browsers (e.g.
+//! Snap/Flatpak builds of Firefox or Brave) run in a sandbox that can't
+//! access `file://` URLs under `~/.rustup`; serving the same static files
+//! over `http://127.0.0.1` sidesteps that restriction entirely.
+//!
+//! The server binds to `127.0.0.1` only (never exposed on the network) and
+//! rejects any request path that would resolve outside the served directory.
+
+use std::{
+    borrow::Cow,
+    convert::Infallible,
+    io::Write as _,
+    path::{Component, Path, PathBuf},
+    sync::Arc,
+};
+
+use anyhow::{Context, Result, anyhow};
+use clap::Args;
+use http_body_util::Full;
+use hyper::{
+    Request, Response, StatusCode,
+    body::{Bytes, Incoming},
+    header::{CONTENT_LENGTH, CONTENT_TYPE},
+    server::conn::http1,
+    service::service_fn,
+};
+use hyper_util::rt::TokioIo;
+use tokio::net::TcpListener;
+use tracing::info;
+
+use super::topical_doc;
+use crate::{
+    config::{ActiveSource, Cfg},
+    dist::{PartialToolchainDesc, manifest::ComponentStatus},
+    toolchain::DistributableToolchain,
+    utils::{self, ExitCode},
+};
+
+macro_rules! docs_data {
+    (
+        $(
+            $( #[$meta:meta] )*
+            ($ident:ident, $help:expr, $path:expr $(,)?)
+        ),+ $(,)?
+    ) => {
+        #[derive(Debug, Args)]
+        pub(crate) struct DocPage {
+            $(
+                #[doc = $help]
+                #[arg(long, group = "page")]
+                $( #[$meta] )*
+                $ident: bool,
+            )+
+        }
+
+        impl DocPage {
+            fn path_str(&self) -> Option<&'static str> {
+                $( if self.$ident { return Some($path); } )+
+                None
+            }
+        }
+    };
+}
+
+docs_data![
+    // flags can be used to open specific documents, e.g. `rustup doc --nomicon`
+    // tuple elements: document name used as flag, help message, document index path
+    (
+        alloc,
+        "The Rust core allocation and collections library",
+        "alloc/index.html"
+    ),
+    (
+        book,
+        "The Rust Programming Language book",
+        "book/index.html"
+    ),
+    (cargo, "The Cargo Book", "cargo/index.html"),
+    (clippy, "The Clippy Documentation", "clippy/index.html"),
+    (core, "The Rust Core Library", "core/index.html"),
+    (
+        edition_guide,
+        "The Rust Edition Guide",
+        "edition-guide/index.html"
+    ),
+    (
+        embedded_book,
+        "The Embedded Rust Book",
+        "embedded-book/index.html"
+    ),
+    (
+        error_codes,
+        "The Rust Error Codes Index",
+        "error_codes/index.html"
+    ),
+    (
+        nomicon,
+        "The Dark Arts of Advanced and Unsafe Rust Programming",
+        "nomicon/index.html"
+    ),
+    #[arg(long = "proc_macro")]
+    (
+        proc_macro,
+        "A support library for macro authors when defining new macros",
+        "proc_macro/index.html"
+    ),
+    (reference, "The Rust Reference", "reference/index.html"),
+    (releases, "Rust Release Notes", "releases.html"),
+    (
+        rust_by_example,
+        "A collection of runnable examples that illustrate various Rust concepts and standard libraries",
+        "rust-by-example/index.html"
+    ),
+    (
+        rustc,
+        "The compiler for the Rust programming language",
+        "rustc/index.html"
+    ),
+    (
+        rustc_docs,
+        "The API documentation for the Rust compiler and other toolchain components",
+        "rustc-docs/index.html"
+    ),
+    (
+        rustdoc,
+        "Documentation generator for Rust projects",
+        "rustdoc/index.html"
+    ),
+    (std, "Standard library API documentation", "std/index.html"),
+    (
+        style_guide,
+        "The Rust Style Guide",
+        "style-guide/index.html"
+    ),
+    (
+        test,
+        "Support code for rustc's built in unit-test and micro-benchmarking framework",
+        "test/index.html"
+    ),
+    (
+        unstable_book,
+        "The Unstable Book",
+        "unstable-book/index.html"
+    ),
+];
+
+impl DocPage {
+    fn path(&self) -> Option<&'static Path> {
+        self.path_str().map(Path::new)
+    }
+
+    fn name(&self) -> Option<&'static str> {
+        Some(self.path_str()?.rsplit_once('/')?.0)
+    }
+
+    fn resolve<'t>(&self, root: &Path, topic: &'t str) -> Option<(PathBuf, Option<&'t str>)> {
+        // Use `.parent()` to chop off the default top-level `index.html`.
+        let mut base = root.join(Path::new(self.path()?).parent()?);
+        base.extend(topic.split("::"));
+        let base_index_html = base.join("index.html");
+
+        if base_index_html.is_file() {
+            return Some((base_index_html, None));
+        }
+
+        let base_html = base.with_extension("html");
+        if base_html.is_file() {
+            return Some((base_html, None));
+        }
+
+        let parent_html = base.parent()?.with_extension("html");
+        if parent_html.is_file() {
+            return Some((parent_html, topic.rsplit_once("::").map(|(_, s)| s)));
+        }
+
+        None
+    }
+}
+
+pub(crate) async fn doc(
+    cfg: &Cfg<'_>,
+    path_only: bool,
+    serve: bool,
+    toolchain: Option<PartialToolchainDesc>,
+    mut topic: Option<&str>,
+    doc_page: &DocPage,
+) -> Result<ExitCode> {
+    let toolchain = toolchain.map(|desc| (desc, ActiveSource::CommandLine));
+    let toolchain = cfg.toolchain_from_partial(toolchain).await?.0;
+
+    if let Ok(distributable) = DistributableToolchain::try_from(&toolchain)
+        && let [_] = distributable
+            .components()?
+            .into_iter()
+            .filter(|cstatus| cstatus.component.short_name() == "rust-docs" && !cstatus.installed)
+            .take(1)
+            .collect::<Vec<ComponentStatus>>()
+            .as_slice()
+    {
+        info!(
+            "`rust-docs` not installed in toolchain `{}`\nhelp: run `rustup component add --toolchain {} rust-docs` to install it",
+            distributable.desc(),
+            distributable.desc()
+        );
+        return Err(anyhow!(
+            "unable to view documentation which is not installed"
+        ));
+    };
+
+    let (doc_path, fragment) = match (topic, doc_page.name()) {
+        (Some(topic), Some(name)) => {
+            let (doc_path, fragment) = doc_page
+                .resolve(&toolchain.doc_path("")?, topic)
+                .context(format!("no document for {name} on {topic}"))?;
+            (Cow::Owned(doc_path), fragment)
+        }
+        (Some(topic), None) => {
+            let doc_path = topical_doc::local_path(&toolchain.doc_path("").unwrap(), topic)?;
+            (Cow::Owned(doc_path), None)
+        }
+        (None, name) => {
+            topic = name;
+            let doc_path = doc_page.path().unwrap_or_else(|| Path::new("index.html"));
+            (Cow::Borrowed(doc_path), None)
+        }
+    };
+
+    if path_only {
+        let doc_path = toolchain.doc_path(&doc_path)?;
+        writeln!(cfg.process.stdout().lock(), "{}", doc_path.display())?;
+        return Ok(ExitCode::SUCCESS);
+    }
+
+    if serve {
+        let root = toolchain.doc_path("")?;
+        serve_and_open(root, &doc_path, fragment).await?;
+        return Ok(ExitCode::SUCCESS);
+    }
+
+    if let Some(name) = topic {
+        info!("opening docs named `{name}` in your browser");
+    } else {
+        info!("opening docs in your browser");
+    }
+    toolchain.open_docs(&doc_path, fragment)?;
+    Ok(ExitCode::SUCCESS)
+}
+
+#[cfg(not(windows))]
+pub(crate) async fn man(
+    cfg: &Cfg<'_>,
+    command: &str,
+    toolchain: Option<PartialToolchainDesc>,
+) -> Result<ExitCode> {
+    let toolchain = toolchain.map(|desc| (desc, ActiveSource::CommandLine));
+    let toolchain = cfg.toolchain_from_partial(toolchain).await?.0;
+    let path = toolchain.man_path();
+    utils::assert_is_directory(&path)?;
+
+    let mut manpaths = std::ffi::OsString::from(path);
+    manpaths.push(":"); // prepend to the default MANPATH list
+    if let Some(path) = cfg.process.var_os("MANPATH") {
+        manpaths.push(path);
+    }
+    std::process::Command::new("man")
+        .env("MANPATH", manpaths)
+        .arg(command)
+        .status()
+        .expect("failed to open man page");
+    Ok(ExitCode::SUCCESS)
+}
+
+/// Blocks forever, accepting and serving connections until the process is
+/// killed by Ctrl-C.
+async fn serve_and_open(root: PathBuf, initial_path: &Path, fragment: Option<&str>) -> Result<()> {
+    let listener = TcpListener::bind(("127.0.0.1", 0))
+        .await
+        .context("failed to bind local documentation server")?;
+    let addr = listener
+        .local_addr()
+        .context("failed to read local address")?;
+    let root = Arc::<Path>::from(root);
+
+    let mut url = format!(
+        "http://{addr}/{}",
+        initial_path.to_string_lossy().replace('\\', "/")
+    );
+    if let Some(fragment) = fragment {
+        url.push('#');
+        url.push_str(fragment);
+    }
+
+    info!("serving docs at {url} (press Ctrl-C to stop)");
+    utils::open_browser(&url)?;
+
+    loop {
+        let (stream, _) = match listener.accept().await {
+            Ok(accepted) => accepted,
+            Err(err) => {
+                tracing::warn!("doc server: failed to accept connection: {err}");
+                continue;
+            }
+        };
+        let io = TokioIo::new(stream);
+        let root = root.clone();
+        let svc = service_fn(move |req| serve(req, root.clone()));
+
+        tokio::spawn(async move {
+            if let Err(err) = http1::Builder::new().serve_connection(io, svc).await {
+                tracing::warn!("doc server: connection error: {err}");
+            }
+        });
+    }
+}
+
+async fn serve(
+    req: Request<Incoming>,
+    root: Arc<Path>,
+) -> Result<Response<Full<Bytes>>, Infallible> {
+    let request_path = req.uri().path().trim_start_matches('/');
+    let mut path = root.to_path_buf();
+    for segment in Path::new(request_path).components() {
+        match segment {
+            Component::Normal(part) => path.push(part),
+            _ => return Ok(not_found()),
+        }
+    }
+    if !path.starts_with(&root) {
+        return Ok(not_found());
+    }
+    if path.is_dir() {
+        path.push("index.html");
+    }
+
+    let Ok(contents) = tokio::fs::read(&path).await else {
+        return Ok(not_found());
+    };
+
+    let response = Response::builder()
+        .status(StatusCode::OK)
+        .header(
+            CONTENT_TYPE,
+            match path.extension().and_then(|ext| ext.to_str()) {
+                Some("html") => "text/html; charset=utf-8",
+                Some("css") => "text/css",
+                Some("js") => "text/javascript",
+                Some("svg") => "image/svg+xml",
+                Some("png") => "image/png",
+                Some("jpg" | "jpeg") => "image/jpeg",
+                Some("woff2") => "font/woff2",
+                Some("txt") => "text/plain; charset=utf-8",
+                _ => "application/octet-stream",
+            },
+        )
+        .header(CONTENT_LENGTH, contents.len())
+        .body(Full::new(Bytes::from(contents)))
+        .expect("building a static response can't fail");
+    Ok(response)
+}
+
+fn not_found() -> Response<Full<Bytes>> {
+    Response::builder()
+        .status(StatusCode::NOT_FOUND)
+        .body(Full::new(Bytes::from_static(b"404 not found")))
+        .expect("building a static response can't fail")
+}
diff --git a/src/cli/help.rs b/src/cli/help.rs
index 015e847077..333cf047ac 100644
--- a/src/cli/help.rs
+++ b/src/cli/help.rs
@@ -212,7 +212,7 @@ pub(crate) fn run_help() -> String {
 
     {LITERAL}$ cargo +nightly build{LITERAL:#}
 
-    {LITERAL}$ rustup run nightly cargo build{LITERAL:#}"
+    {LITERAL}$ rustup run --install nightly cargo build{LITERAL:#}"
     )
 }
 
@@ -232,7 +232,11 @@ pub(crate) fn doc_help() -> String {
   the default browser.
 
   By default, it opens the documentation index. Use the various
-  flags to open specific pieces of documentation."
+  flags to open specific pieces of documentation.
+
+  If your browser is sandboxed (e.g. installed via Snap or Flatpak) it
+  may be unable to open `file://` URLs under `~/.rustup`. Pass `--serve`
+  to serve the documentation over a local HTTP server instead."
     )
 }
 
diff --git a/src/cli/proxy_mode.rs b/src/cli/proxy_mode.rs
index 0e480e920f..4b7ac55d49 100644
--- a/src/cli/proxy_mode.rs
+++ b/src/cli/proxy_mode.rs
@@ -1,4 +1,4 @@
-use std::{path::PathBuf, process::ExitStatus};
+use std::{path::PathBuf, process::ExitStatus, str::FromStr};
 
 use anyhow::Result;
 
@@ -23,7 +23,7 @@ pub async fn main(arg0: &str, current_dir: PathBuf, process: &Process) -> Result
         .as_ref()
         .map(|arg| arg.to_string_lossy())
         .filter(|arg| arg.starts_with('+'))
-        .map(|name| ResolvableLocalToolchainName::try_from(&name.as_ref()[1..]))
+        .map(|name| ResolvableLocalToolchainName::from_str(&name[1..]))
         .transpose()?;
 
     // Build command args now while we know whether or not to skip arg 1.
diff --git a/src/cli/rustup_mode.rs b/src/cli/rustup_mode.rs
index 343eccd504..8dbe6dad5d 100644
--- a/src/cli/rustup_mode.rs
+++ b/src/cli/rustup_mode.rs
@@ -12,7 +12,7 @@ use std::{
 
 use anstream::ColorChoice;
 use anstyle::Style;
-use anyhow::{Context, Error, Result, anyhow};
+use anyhow::{Error, Result, anyhow};
 use clap::{
     Args, CommandFactory, Parser, Subcommand, ValueEnum,
     builder::{PossibleValue, ValueHint},
@@ -29,6 +29,7 @@ use tracing_subscriber::{EnvFilter, Registry, reload::Handle};
 use crate::{
     cli::{
         common::{self, PackageUpdate, update_console_filter},
+        docs,
         errors::CliError,
         help::{
             check_help, completions_help, default_help, doc_help, install_help,
@@ -39,14 +40,13 @@ use crate::{
             update_help,
         },
         self_update::{self, SelfUpdateMode, check_rustup_update},
-        topical_doc,
     },
     command, component_for_bin,
     config::{ActiveSource, Cfg},
     dist::{
         AutoInstallMode, DistOptions, PartialToolchainDesc, Profile, TargetTuple,
         download::DownloadCfg,
-        manifest::{Component, ComponentStatus, ManifestWithHash},
+        manifest::{Component, ManifestWithHash},
     },
     errors::{DEFAULT_STABLE_HINT, RustupError},
     install::{InstallMethod, UpdateStatus},
@@ -111,7 +111,7 @@ struct Rustup {
 fn plus_toolchain_value_parser(s: &str) -> clap::error::Result<ResolvableToolchainName> {
     use clap::{Error, error::ErrorKind};
     if let Some(stripped) = s.strip_prefix('+') {
-        ResolvableToolchainName::try_from(stripped)
+        ResolvableToolchainName::from_str(stripped)
             .map_err(|e| Error::raw(ErrorKind::InvalidValue, e))
     } else {
         Err(Error::raw(
@@ -252,6 +252,11 @@ enum RustupSubcmd {
         #[arg(long)]
         path: bool,
 
+        /// Serve the documentation over a local HTTP server instead of
+        /// opening it directly as a `file://` URL
+        #[arg(long, conflicts_with = "path")]
+        serve: bool,
+
         #[arg(long, help = official_toolchain_arg_help())]
         toolchain: Option<PartialToolchainDesc>,
 
@@ -259,7 +264,7 @@ enum RustupSubcmd {
         topic: Option<String>,
 
         #[command(flatten)]
-        page: DocPage,
+        page: docs::DocPage,
     },
 
     /// View the man page for a given command
@@ -468,6 +473,10 @@ struct UpdateOpts {
     /// Set the installed toolchain as the override for the current directory
     #[arg(long)]
     r#override: bool,
+
+    /// Set the installed toolchain as the default toolchain
+    #[arg(long)]
+    default: bool,
 }
 
 #[derive(Debug, Default, Args)]
@@ -801,18 +810,19 @@ pub async fn main(
         RustupSubcmd::Which { command, toolchain } => which(cfg, &command, toolchain).await,
         RustupSubcmd::Doc {
             path,
+            serve,
             toolchain,
             topic,
             page,
-        } => doc(cfg, path, toolchain, topic.as_deref(), &page).await,
+        } => docs::doc(cfg, path, serve, toolchain, topic.as_deref(), &page).await,
         #[cfg(not(windows))]
-        RustupSubcmd::Man { command, toolchain } => man(cfg, &command, toolchain).await,
+        RustupSubcmd::Man { command, toolchain } => docs::man(cfg, &command, toolchain).await,
         RustupSubcmd::Self_ { subcmd } => match subcmd {
             SelfSubcmd::Update => self_update::update(cfg).await,
             SelfSubcmd::Uninstall {
                 no_prompt,
                 no_modify_path,
-            } => self_update::uninstall(no_prompt, no_modify_path, process),
+            } => self_update::uninstall(no_prompt, no_modify_path, cfg),
             SelfSubcmd::UpgradeData => cfg.upgrade_data().map(|_| ExitCode::SUCCESS),
         },
         RustupSubcmd::Set { subcmd } => match subcmd {
@@ -854,7 +864,7 @@ async fn default_(
                 cfg.set_default(None)?;
             }
             MaybeResolvableToolchainName::Some(ResolvableToolchainName::Custom(toolchain_name)) => {
-                Toolchain::new(cfg, (&toolchain_name).into())?;
+                Toolchain::new(cfg, toolchain_name.clone().into())?;
                 cfg.set_default(Some(&toolchain_name.into()))?;
             }
             MaybeResolvableToolchainName::Some(ResolvableToolchainName::Official(toolchain)) => {
@@ -1040,7 +1050,6 @@ async fn update(
     let self_update_mode = SelfUpdateMode::from_cfg(cfg)?;
     let should_self_update = !opts.no_self_update;
     let force_non_host = opts.force_non_host;
-    let set_override = opts.r#override;
     cfg.profile_override = opts.profile;
 
     let cfg = &cfg;
@@ -1099,11 +1108,13 @@ async fn update(
                 Ok(status.clone()),
             )?;
 
-            if set_override {
+            if opts.r#override {
                 cfg.make_override(&cfg.current_dir, &desc.clone().into())?;
             }
 
-            if cfg.get_default()?.is_none() && matches!(status, UpdateStatus::Installed) {
+            if opts.default
+                || (cfg.get_default()?.is_none() && matches!(status, UpdateStatus::Installed))
+            {
                 cfg.set_default(Some(&desc.into()))?;
             }
         }
@@ -1717,236 +1728,6 @@ fn override_remove(cfg: &Cfg<'_>, path: Option<&Path>, nonexistent: bool) -> Res
     Ok(ExitCode::SUCCESS)
 }
 
-macro_rules! docs_data {
-    (
-        $(
-            $( #[$meta:meta] )*
-            ($ident:ident, $help:expr, $path:expr $(,)?)
-        ),+ $(,)?
-    ) => {
-        #[derive(Debug, Args)]
-        struct DocPage {
-            $(
-                #[doc = $help]
-                #[arg(long, group = "page")]
-                $( #[$meta] )*
-                $ident: bool,
-            )+
-        }
-
-        impl DocPage {
-            fn path_str(&self) -> Option<&'static str> {
-                $( if self.$ident { return Some($path); } )+
-                None
-            }
-        }
-    };
-}
-
-docs_data![
-    // flags can be used to open specific documents, e.g. `rustup doc --nomicon`
-    // tuple elements: document name used as flag, help message, document index path
-    (
-        alloc,
-        "The Rust core allocation and collections library",
-        "alloc/index.html"
-    ),
-    (
-        book,
-        "The Rust Programming Language book",
-        "book/index.html"
-    ),
-    (cargo, "The Cargo Book", "cargo/index.html"),
-    (clippy, "The Clippy Documentation", "clippy/index.html"),
-    (core, "The Rust Core Library", "core/index.html"),
-    (
-        edition_guide,
-        "The Rust Edition Guide",
-        "edition-guide/index.html"
-    ),
-    (
-        embedded_book,
-        "The Embedded Rust Book",
-        "embedded-book/index.html"
-    ),
-    (
-        error_codes,
-        "The Rust Error Codes Index",
-        "error_codes/index.html"
-    ),
-    (
-        nomicon,
-        "The Dark Arts of Advanced and Unsafe Rust Programming",
-        "nomicon/index.html"
-    ),
-    #[arg(long = "proc_macro")]
-    (
-        proc_macro,
-        "A support library for macro authors when defining new macros",
-        "proc_macro/index.html"
-    ),
-    (reference, "The Rust Reference", "reference/index.html"),
-    (releases, "Rust Release Notes", "releases.html"),
-    (
-        rust_by_example,
-        "A collection of runnable examples that illustrate various Rust concepts and standard libraries",
-        "rust-by-example/index.html"
-    ),
-    (
-        rustc,
-        "The compiler for the Rust programming language",
-        "rustc/index.html"
-    ),
-    (
-        rustc_docs,
-        "The API documentation for the Rust compiler and other toolchain components",
-        "rustc-docs/index.html"
-    ),
-    (
-        rustdoc,
-        "Documentation generator for Rust projects",
-        "rustdoc/index.html"
-    ),
-    (std, "Standard library API documentation", "std/index.html"),
-    (
-        style_guide,
-        "The Rust Style Guide",
-        "style-guide/index.html"
-    ),
-    (
-        test,
-        "Support code for rustc's built in unit-test and micro-benchmarking framework",
-        "test/index.html"
-    ),
-    (
-        unstable_book,
-        "The Unstable Book",
-        "unstable-book/index.html"
-    ),
-];
-
-impl DocPage {
-    fn path(&self) -> Option<&'static Path> {
-        self.path_str().map(Path::new)
-    }
-
-    fn name(&self) -> Option<&'static str> {
-        Some(self.path_str()?.rsplit_once('/')?.0)
-    }
-
-    fn resolve<'t>(&self, root: &Path, topic: &'t str) -> Option<(PathBuf, Option<&'t str>)> {
-        // Use `.parent()` to chop off the default top-level `index.html`.
-        let mut base = root.join(Path::new(self.path()?).parent()?);
-        base.extend(topic.split("::"));
-        let base_index_html = base.join("index.html");
-
-        if base_index_html.is_file() {
-            return Some((base_index_html, None));
-        }
-
-        let base_html = base.with_extension("html");
-        if base_html.is_file() {
-            return Some((base_html, None));
-        }
-
-        let parent_html = base.parent()?.with_extension("html");
-        if parent_html.is_file() {
-            return Some((parent_html, topic.rsplit_once("::").map(|(_, s)| s)));
-        }
-
-        None
-    }
-}
-
-async fn doc(
-    cfg: &Cfg<'_>,
-    path_only: bool,
-    toolchain: Option<PartialToolchainDesc>,
-    mut topic: Option<&str>,
-    doc_page: &DocPage,
-) -> Result<ExitCode> {
-    let toolchain = toolchain.map(|desc| (desc, ActiveSource::CommandLine));
-    let toolchain = cfg.toolchain_from_partial(toolchain).await?.0;
-
-    if let Ok(distributable) = DistributableToolchain::try_from(&toolchain)
-        && let [_] = distributable
-            .components()?
-            .into_iter()
-            .filter(|cstatus| cstatus.component.short_name() == "rust-docs" && !cstatus.installed)
-            .take(1)
-            .collect::<Vec<ComponentStatus>>()
-            .as_slice()
-    {
-        info!(
-            "`rust-docs` not installed in toolchain `{}`\nhelp: run `rustup component add --toolchain {} rust-docs` to install it",
-            distributable.desc(),
-            distributable.desc()
-        );
-        return Err(anyhow!(
-            "unable to view documentation which is not installed"
-        ));
-    };
-
-    let (doc_path, fragment) = match (topic, doc_page.name()) {
-        (Some(topic), Some(name)) => {
-            let (doc_path, fragment) = doc_page
-                .resolve(&toolchain.doc_path("")?, topic)
-                .context(format!("no document for {name} on {topic}"))?;
-            (Cow::Owned(doc_path), fragment)
-        }
-        (Some(topic), None) => {
-            let doc_path = topical_doc::local_path(&toolchain.doc_path("").unwrap(), topic)?;
-            (Cow::Owned(doc_path), None)
-        }
-        (None, name) => {
-            topic = name;
-            let doc_path = doc_page.path().unwrap_or_else(|| Path::new("index.html"));
-            (Cow::Borrowed(doc_path), None)
-        }
-    };
-
-    if path_only {
-        let doc_path = toolchain.doc_path(&doc_path)?;
-        writeln!(cfg.process.stdout().lock(), "{}", doc_path.display())?;
-        return Ok(ExitCode::SUCCESS);
-    }
-
-    if let Some(name) = topic {
-        writeln!(
-            cfg.process.stderr().lock(),
-            "Opening docs named `{name}` in your browser"
-        )?;
-    } else {
-        writeln!(cfg.process.stderr().lock(), "Opening docs in your browser")?;
-    }
-    toolchain.open_docs(&doc_path, fragment)?;
-    Ok(ExitCode::SUCCESS)
-}
-
-#[cfg(not(windows))]
-async fn man(
-    cfg: &Cfg<'_>,
-    command: &str,
-    toolchain: Option<PartialToolchainDesc>,
-) -> Result<ExitCode> {
-    let toolchain = toolchain.map(|desc| (desc, ActiveSource::CommandLine));
-    let toolchain = cfg.toolchain_from_partial(toolchain).await?.0;
-    let path = toolchain.man_path();
-    utils::assert_is_directory(&path)?;
-
-    let mut manpaths = std::ffi::OsString::from(path);
-    manpaths.push(":"); // prepend to the default MANPATH list
-    if let Some(path) = cfg.process.var_os("MANPATH") {
-        manpaths.push(path);
-    }
-    std::process::Command::new("man")
-        .env("MANPATH", manpaths)
-        .arg(command)
-        .status()
-        .expect("failed to open man page");
-    Ok(ExitCode::SUCCESS)
-}
-
 fn set_auto_self_update(cfg: &Cfg<'_>, auto_self_update_mode: SelfUpdateMode) -> Result<ExitCode> {
     if cfg!(feature = "no-self-update") {
         let mut args = cfg.process.args_os();
@@ -2041,7 +1822,7 @@ async fn display_version(current_dir: PathBuf, process: &Process) -> Result<()>
     cfg.toolchain_override = cfg
         .process
         .args()
-        .find_map(|arg| arg.strip_prefix('+').map(ResolvableToolchainName::try_from))
+        .find_map(|arg| arg.strip_prefix('+').map(ResolvableToolchainName::from_str))
         .transpose()?;
 
     match cfg.maybe_ensure_active_toolchain(None).await {
diff --git a/src/cli/self_update.rs b/src/cli/self_update.rs
index cfe7ef0ed5..88bc516f81 100644
--- a/src/cli/self_update.rs
+++ b/src/cli/self_update.rs
@@ -30,21 +30,21 @@
 //! Deleting the running binary during uninstall is tricky
 //! and racy on Windows.
 
-use std::borrow::Cow;
-use std::env::{self, consts::EXE_SUFFIX};
 #[cfg(not(windows))]
 use std::io;
-use std::io::Write;
-use std::path::{Component, MAIN_SEPARATOR, Path, PathBuf};
-use std::process::Command;
-use std::str::FromStr;
-use std::{fmt, fs};
+use std::{
+    borrow::Cow,
+    env::{self, consts::EXE_SUFFIX},
+    fmt, fs,
+    io::Write,
+    path::{Component, MAIN_SEPARATOR, Path, PathBuf},
+    process::Command,
+    str::FromStr,
+};
 
 use anstyle::Style;
 use anyhow::{Context, Result, anyhow};
-use cfg_if::cfg_if;
-use clap::ValueEnum;
-use clap::builder::PossibleValue;
+use clap::{ValueEnum, builder::PossibleValue};
 use clap_cargo::style::{GOOD, WARN};
 use itertools::Itertools;
 use same_file::Handle;
@@ -58,7 +58,7 @@ use crate::{
         errors::CliError,
         markdown::md,
     },
-    config::Cfg,
+    config::{Cfg, default_host_tuple},
     dist::{
         DistOptions, PartialToolchainDesc, Profile, TargetTuple, ToolchainDesc,
         download::DownloadCfg,
@@ -67,6 +67,7 @@ use crate::{
     errors::RustupError,
     install::{InstallMethod, UpdateStatus},
     process::Process,
+    settings::SettingsFile,
     toolchain::{
         DistributableToolchain, MaybeOfficialToolchainName, ResolvableToolchainName, Toolchain,
         ToolchainName,
@@ -74,6 +75,9 @@ use crate::{
     utils::{self, ExitCode},
 };
 
+#[macro_use]
+mod msg;
+
 #[cfg(unix)]
 mod shell;
 
@@ -89,7 +93,7 @@ mod windows;
 #[cfg(windows)]
 pub use windows::complete_windows_uninstall;
 #[cfg(all(windows, feature = "test"))]
-pub use windows::{RegistryGuard, RegistryValueId, USER_PATH, get_path};
+pub use windows::{RUSTUP_REGISTRY_TEST_ID, RegistryValueId, USER_PATH, get_path};
 #[cfg(windows)]
 use windows::{delete_rustup_and_cargo_home, do_add_to_path, do_remove_from_path};
 #[cfg(windows)]
@@ -106,7 +110,193 @@ pub(crate) struct InstallOpts<'a> {
 }
 
 impl InstallOpts<'_> {
-    fn install(self, cfg: &mut Cfg<'_>) -> Result<Option<ToolchainDesc>> {
+    /// Installs rustup to the system according to the current options.
+    ///
+    /// The installation process is composed of the following steps:
+    /// - Copying the running binary to the binary directory.
+    /// - Hard-linking the various Rust tools to that copied binary.
+    /// - Adding the binary directory to the `$PATH` unless `no_modify_path` is set.
+    pub(crate) async fn install(
+        mut self,
+        current_dir: PathBuf,
+        no_prompt: bool,
+        quiet: bool,
+        process: &Process,
+    ) -> Result<ExitCode> {
+        #[cfg_attr(not(unix), allow(unused_mut))]
+        let mut exit_code = ExitCode::SUCCESS;
+
+        self.validate(process).map_err(|e| {
+            anyhow!(
+                "Pre-checks for host and toolchain failed: {e}\n\
+            If you are unsure of suitable values, the 'stable' toolchain is the default.\n\
+            Valid host tuples look something like: {}",
+                TargetTuple::from_host_or_build(process)
+            )
+        })?;
+
+        if process
+            .var_os("RUSTUP_INIT_SKIP_EXISTENCE_CHECKS")
+            .is_none_or(|s| s != "yes")
+        {
+            check_existence_of_rustc_or_cargo_in_path(no_prompt, process)?;
+            check_existence_of_settings_file(process)?;
+        }
+
+        #[cfg(unix)]
+        {
+            exit_code &= unix::do_anti_sudo_check(no_prompt, process)?;
+        }
+
+        let mut term = process.stdout();
+
+        #[cfg(windows)]
+        windows::maybe_install_msvc(&mut term, no_prompt, quiet, &self, process).await?;
+
+        if !no_prompt {
+            let msg = pre_install_msg(self.no_modify_path, process)?;
+
+            md(&mut term, msg);
+            let mut customized_install = false;
+            loop {
+                md(&mut term, self.display(process));
+                match common::confirm_advanced(customized_install, process)? {
+                    Confirm::No => {
+                        info!("aborting installation");
+                        return Ok(ExitCode::SUCCESS);
+                    }
+                    Confirm::Yes => break,
+                    Confirm::Advanced => {
+                        customized_install = true;
+                        self.customize(process)?;
+                    }
+                }
+            }
+        }
+
+        let no_modify_path = self.no_modify_path;
+        if let Err(e) = self.install_rust(current_dir, quiet, process).await {
+            report_error(&e, process);
+
+            // On windows, where installation happens in a console
+            // that may have opened just for this purpose, give
+            // the user an opportunity to see the error before the
+            // window closes.
+            #[cfg(windows)]
+            if !no_prompt {
+                windows::ensure_prompt(process)?;
+            }
+
+            return Ok(ExitCode::FAILURE);
+        }
+
+        let cargo_home = canonical_cargo_home(process)?;
+        #[cfg(windows)]
+        let cargo_home = cargo_home.replace('\\', r"\\");
+        #[cfg(windows)]
+        let msg = if no_modify_path {
+            format!(
+                post_install_msg_win_no_modify_path!(),
+                cargo_home = cargo_home
+            )
+        } else {
+            format!(post_install_msg_win!(), cargo_home = cargo_home)
+        };
+        #[cfg(not(windows))]
+        let source_env_lines = shell::build_source_env_lines(process);
+        #[cfg(not(windows))]
+        let msg = if no_modify_path {
+            format!(
+                post_install_msg_unix_no_modify_path!(),
+                cargo_home = cargo_home,
+                source_env_lines = source_env_lines,
+            )
+        } else {
+            format!(
+                post_install_msg_unix!(),
+                cargo_home = cargo_home,
+                source_env_lines = source_env_lines,
+            )
+        };
+        md(&mut term, msg);
+
+        #[cfg(unix)]
+        warn_if_default_linker_missing(process);
+
+        #[cfg(windows)]
+        if !no_prompt {
+            // On windows, where installation happens in a console
+            // that may have opened just for this purpose, require
+            // the user to press a key to continue.
+            windows::ensure_prompt(process)?;
+        }
+
+        Ok(exit_code)
+    }
+
+    /// Installs the rustup binary and proxies, and installs a toolchain if specified.
+    async fn install_rust(
+        self,
+        current_dir: PathBuf,
+        quiet: bool,
+        process: &Process,
+    ) -> Result<()> {
+        install_bins(process)?;
+
+        #[cfg(unix)]
+        unix::do_write_env_files(process)?;
+
+        if !self.no_modify_path {
+            do_add_to_path(process)?;
+        }
+
+        // If RUSTUP_HOME is not set, make sure it exists
+        if process.var_os("RUSTUP_HOME").is_none() {
+            let home = process
+                .home_dir()
+                .map(|p| p.join(".rustup"))
+                .ok_or_else(|| anyhow::anyhow!("could not find home dir to put .rustup in"))?;
+
+            fs::create_dir_all(home).context("unable to create ~/.rustup")?;
+        }
+
+        let mut cfg = Cfg::from_env(current_dir, quiet, false, process)?;
+
+        let (components, targets) = (self.components, self.targets);
+        let toolchain = self.select_toolchain(&mut cfg)?;
+        if let Some(desc) = toolchain {
+            let options =
+                DistOptions::new(components, targets, &desc, cfg.get_profile()?, true, &cfg)?;
+            let status = if Toolchain::exists(&cfg, &desc.clone().into())? {
+                warn!("Updating existing toolchain, profile choice will be ignored");
+                // If we have a partial install we might not be able to read content here. We could:
+                // - fail and folk have to delete the partially present toolchain to recover
+                // - silently ignore it (and provide inconsistent metadata for reporting the install/update change)
+                // - delete the partial install and start over
+                // For now, we error.
+                let toolchain = DistributableToolchain::new(&cfg, desc.clone())?;
+                InstallMethod::Dist(options.for_update(&toolchain, false))
+                    .install(None)
+                    .await?
+            } else {
+                DistributableToolchain::install(options).await?.status
+            };
+
+            check_proxy_sanity(cfg.process, components, &desc)?;
+
+            cfg.set_default(Some(&desc.clone().into()))?;
+            writeln!(cfg.process.stdout().lock())?;
+            common::show_channel_update(&cfg, PackageUpdate::Toolchain(desc), Ok(status))?;
+        }
+        Ok(())
+    }
+
+    /// Selects the toolchain to install based on the user's intent.
+    ///
+    /// This function first initializes the default profile and default host tuple in the
+    /// configuration, then returns the toolchain that should be installed, or `None` if none is
+    /// specified by the user.
+    fn select_toolchain(self, cfg: &mut Cfg<'_>) -> Result<Option<ToolchainDesc>> {
         let Self {
             default_host_tuple,
             default_toolchain,
@@ -204,14 +394,16 @@ impl InstallOpts<'_> {
             process,
         )?);
 
-        self.default_toolchain = Some(MaybeOfficialToolchainName::try_from(common::question_str(
-            "Default toolchain? (stable/beta/nightly/none)",
-            &match &self.default_toolchain {
-                Some(name) => name.to_string(),
-                None => "stable".to_owned(),
-            },
-            process,
-        )?)?);
+        self.default_toolchain = Some(MaybeOfficialToolchainName::from_str(
+            &common::question_str(
+                "Default toolchain? (stable/beta/nightly/none)",
+                &match &self.default_toolchain {
+                    Some(name) => name.to_string(),
+                    None => "stable".to_owned(),
+                },
+                process,
+            )?,
+        )?);
 
         self.profile = <Profile as FromStr>::from_str(&common::question_str(
             &format!(
@@ -238,7 +430,7 @@ impl InstallOpts<'_> {
             .unwrap_or_else(|| TargetTuple::from_host_or_build(process));
         let partial_channel = match &self.default_toolchain {
             None | Some(MaybeOfficialToolchainName::None) => {
-                ResolvableToolchainName::try_from("stable")?
+                ResolvableToolchainName::from_str("stable")?
             }
             Some(MaybeOfficialToolchainName::Some(s)) => s.into(),
         };
@@ -246,6 +438,28 @@ impl InstallOpts<'_> {
         trace!("Successfully resolved installation toolchain as: {resolved}");
         Ok(())
     }
+
+    fn display(&self, process: &Process) -> String {
+        format!(
+            r"Current installation options:
+
+- `  `default host tuple: `{}`
+- `   `default toolchain: `{}`
+- `             `profile: `{}`
+- modify PATH variable: `{}`
+",
+            self.default_host_tuple.as_ref().map_or_else(
+                || TargetTuple::from_host_or_build(process),
+                TargetTuple::new,
+            ),
+            match &self.default_toolchain {
+                Some(name) => name.to_string(),
+                None => "stable (default)".to_owned(),
+            },
+            self.profile,
+            if !self.no_modify_path { "yes" } else { "no" }
+        )
+    }
 }
 
 #[derive(Clone, Copy, Debug, Default, Deserialize, Eq, PartialEq, Serialize)]
@@ -322,7 +536,7 @@ impl SelfUpdateMode {
         let setup_path = prepare_update(dl_cfg).await?;
 
         if let Some(setup_path) = &setup_path {
-            return run_update(setup_path);
+            return run_update(setup_path, dl_cfg.process);
         } else {
             // Try again in case we emitted "tool `{}` is already installed" last time.
             install_proxies(dl_cfg.process)?;
@@ -369,157 +583,6 @@ impl fmt::Display for SelfUpdateMode {
     }
 }
 
-// The big installation messages. These are macros because the first
-// argument of format! needs to be a literal.
-
-macro_rules! pre_install_msg_template {
-    ($platform_msg:literal) => {
-        concat!(
-            r"
-# Welcome to Rust!
-
-This will download and install the official compiler for the Rust
-programming language, and its package manager, Cargo.
-
-Rustup metadata and toolchains will be installed into the Rustup
-home directory, located at:
-
-    {rustup_home}
-
-This can be modified with the RUSTUP_HOME environment variable.
-
-The Cargo home directory is located at:
-
-    {cargo_home}
-
-This can be modified with the CARGO_HOME environment variable.
-
-The `cargo`, `rustc`, `rustup` and other commands will be added to
-Cargo's bin directory, located at:
-
-    {cargo_home_bin}
-
-",
-            $platform_msg,
-            r#"
-
-You can uninstall at any time with `rustup self uninstall` and
-these changes will be reverted.
-"#
-        )
-    };
-}
-
-#[cfg(not(windows))]
-macro_rules! pre_install_msg_unix {
-    () => {
-        pre_install_msg_template!(
-            "This path will then be added to your `PATH` environment variable by
-modifying the profile file{plural} located at:
-
-{rcfiles}"
-        )
-    };
-}
-
-#[cfg(windows)]
-macro_rules! pre_install_msg_win {
-    () => {
-        pre_install_msg_template!(
-            r#"This path will then be added to your `PATH` environment variable by
-modifying the `PATH` registry key at `HKEY_CURRENT_USER\Environment`."#
-        )
-    };
-}
-
-macro_rules! pre_install_msg_no_modify_path {
-    () => {
-        pre_install_msg_template!(
-            "This path needs to be in your `PATH` environment variable,
-but will not be added automatically."
-        )
-    };
-}
-
-#[cfg(not(windows))]
-macro_rules! post_install_msg_unix {
-    () => {
-        r"# Rust is installed now. Great!
-
-To get started you may need to restart your current shell.
-This would reload your `PATH` environment variable to include
-Cargo's bin directory ({cargo_home}/bin).
-
-To configure your current shell, you need to source the
-corresponding `env` file under {cargo_home}.
-
-Consider running the right command for your shell (note the leading DOT):
-{source_env_lines}"
-    };
-}
-
-#[cfg(windows)]
-macro_rules! post_install_msg_win {
-    () => {
-        r"# Rust is installed now. Great!
-
-
-To get started you may need to restart your current shell.
-This would reload its `PATH` environment variable to include
-Cargo's bin directory ({cargo_home}\\bin).
-"
-    };
-}
-
-#[cfg(not(windows))]
-macro_rules! post_install_msg_unix_no_modify_path {
-    () => {
-        r"# Rust is installed now. Great!
-
-To get started you need Cargo's bin directory ({cargo_home}/bin) in your `PATH`
-environment variable. This has not been done automatically.
-
-To configure your current shell, you need to source
-the corresponding `env` file under {cargo_home}.
-
-Consider running the right command for your shell (note the leading DOT):
-{source_env_lines}"
-    };
-}
-
-#[cfg(windows)]
-macro_rules! post_install_msg_win_no_modify_path {
-    () => {
-        r"# Rust is installed now. Great!
-
-To get started you need Cargo's bin directory ({cargo_home}\\bin) in your `PATH`
-environment variable. This has not been done automatically.
-"
-    };
-}
-
-macro_rules! pre_uninstall_msg {
-    () => {
-        r"# Thanks for hacking in Rust!
-
-This will uninstall all Rust toolchains and data, and remove
-`{cargo_home}/bin` from your `PATH` environment variable.
-
-"
-    };
-}
-
-macro_rules! pre_uninstall_msg_no_modify_path {
-    () => {
-        r"# Thanks for hacking in Rust!
-
-This will uninstall all Rust toolchains and data.
-Your `PATH` environment variable will not be touched.
-
-"
-    };
-}
-
 static DEFAULT_UPDATE_ROOT: &str = "https://static.rust-lang.org/rustup";
 
 fn update_root(process: &Process) -> String {
@@ -539,140 +602,15 @@ fn canonical_cargo_home(process: &Process) -> Result<Cow<'static, str>> {
         .unwrap_or_else(|| PathBuf::from("."))
         .join(".cargo");
     Ok(if default_cargo_home == path {
-        cfg_if! {
-            if #[cfg(windows)] {
-                r"%USERPROFILE%\.cargo".into()
-            } else {
-                "$HOME/.cargo".into()
-            }
+        cfg_select! {
+            windows => r"%USERPROFILE%\.cargo".into(),
+            _ => "$HOME/.cargo".into(),
         }
     } else {
         path.to_string_lossy().into_owned().into()
     })
 }
 
-/// Installing is a simple matter of copying the running binary to
-/// `CARGO_HOME`/bin, hard-linking the various Rust tools to it,
-/// and adding `CARGO_HOME`/bin to PATH.
-pub(crate) async fn install(
-    no_prompt: bool,
-    mut opts: InstallOpts<'_>,
-    cfg: &mut Cfg<'_>,
-) -> Result<ExitCode> {
-    #[cfg_attr(not(unix), allow(unused_mut))]
-    let mut exit_code = ExitCode::SUCCESS;
-
-    opts.validate(cfg.process).map_err(|e| {
-        anyhow!(
-            "Pre-checks for host and toolchain failed: {e}\n\
-            If you are unsure of suitable values, the 'stable' toolchain is the default.\n\
-            Valid host tuples look something like: {}",
-            TargetTuple::from_host_or_build(cfg.process)
-        )
-    })?;
-
-    if cfg
-        .process
-        .var_os("RUSTUP_INIT_SKIP_EXISTENCE_CHECKS")
-        .is_none_or(|s| s != "yes")
-    {
-        check_existence_of_rustc_or_cargo_in_path(no_prompt, cfg.process)?;
-        check_existence_of_settings_file(cfg)?;
-    }
-
-    #[cfg(unix)]
-    {
-        exit_code &= unix::do_anti_sudo_check(no_prompt, cfg.process)?;
-    }
-
-    let mut term = cfg.process.stdout();
-
-    #[cfg(windows)]
-    windows::maybe_install_msvc(&mut term, no_prompt, &opts, &*cfg).await?;
-
-    if !no_prompt {
-        let msg = pre_install_msg(opts.no_modify_path, cfg.process)?;
-
-        md(&mut term, msg);
-        let mut customized_install = false;
-        loop {
-            md(&mut term, current_install_opts(&opts, cfg.process));
-            match common::confirm_advanced(customized_install, cfg.process)? {
-                Confirm::No => {
-                    info!("aborting installation");
-                    return Ok(ExitCode::SUCCESS);
-                }
-                Confirm::Yes => {
-                    break;
-                }
-                Confirm::Advanced => {
-                    customized_install = true;
-                    opts.customize(cfg.process)?;
-                }
-            }
-        }
-    }
-
-    let no_modify_path = opts.no_modify_path;
-    if let Err(e) = maybe_install_rust(opts, cfg).await {
-        report_error(&e, cfg.process);
-
-        // On windows, where installation happens in a console
-        // that may have opened just for this purpose, give
-        // the user an opportunity to see the error before the
-        // window closes.
-        #[cfg(windows)]
-        if !no_prompt {
-            windows::ensure_prompt(cfg.process)?;
-        }
-
-        return Ok(ExitCode::FAILURE);
-    }
-
-    let cargo_home = canonical_cargo_home(cfg.process)?;
-    #[cfg(windows)]
-    let cargo_home = cargo_home.replace('\\', r"\\");
-    #[cfg(windows)]
-    let msg = if no_modify_path {
-        format!(
-            post_install_msg_win_no_modify_path!(),
-            cargo_home = cargo_home
-        )
-    } else {
-        format!(post_install_msg_win!(), cargo_home = cargo_home)
-    };
-    #[cfg(not(windows))]
-    let source_env_lines = shell::build_source_env_lines(cfg.process);
-    #[cfg(not(windows))]
-    let msg = if no_modify_path {
-        format!(
-            post_install_msg_unix_no_modify_path!(),
-            cargo_home = cargo_home,
-            source_env_lines = source_env_lines,
-        )
-    } else {
-        format!(
-            post_install_msg_unix!(),
-            cargo_home = cargo_home,
-            source_env_lines = source_env_lines,
-        )
-    };
-    md(&mut term, msg);
-
-    #[cfg(unix)]
-    warn_if_default_linker_missing(cfg.process);
-
-    #[cfg(windows)]
-    if !no_prompt {
-        // On windows, where installation happens in a console
-        // that may have opened just for this purpose, require
-        // the user to press a key to continue.
-        windows::ensure_prompt(cfg.process)?;
-    }
-
-    Ok(exit_code)
-}
-
 fn rustc_or_cargo_exists_in_path(process: &Process) -> Result<()> {
     // Ignore rustc and cargo if present in $HOME/.cargo/bin or a few other directories
     #[allow(clippy::ptr_arg)]
@@ -721,23 +659,22 @@ fn check_existence_of_rustc_or_cargo_in_path(no_prompt: bool, process: &Process)
     Ok(())
 }
 
-fn check_existence_of_settings_file(cfg: &Cfg<'_>) -> Result<()> {
-    let rustup_dir = cfg.process.rustup_home()?;
-    let settings_file_path = rustup_dir.join("settings.toml");
-    if !utils::path_exists(&settings_file_path) {
+fn check_existence_of_settings_file(process: &Process) -> Result<()> {
+    let rustup_dir = process.rustup_home()?;
+    let settings_file = SettingsFile::new(rustup_dir.join("settings.toml"));
+    if !utils::path_exists(&settings_file.path) {
         return Ok(());
     }
-    let settings_toolchain = cfg
-        .settings_file
-        .with(|s| Ok(s.default_toolchain.clone()))?;
+    let settings_toolchain = settings_file.with(|s| Ok(s.default_toolchain.clone()))?;
     // If there is already a non-empty `settings.toml` file (e.g., not a fresh install),
     // then we warn the user that there was an already configured default toolchain.
     let Some(default_toolchain) = settings_toolchain else {
         return Ok(());
     };
     warn!("it looks like you have an existing rustup settings file at:");
-    warn!("{}", settings_file_path.display());
-    let inferred = PartialToolchainDesc::from_str("stable")?.resolve(&cfg.default_host_tuple()?)?;
+    warn!("{}", settings_file.path.display());
+    let default_host_tuple = settings_file.with(|s| Ok(default_host_tuple(s, process)))?;
+    let inferred = PartialToolchainDesc::from_str("stable")?.resolve(&default_host_tuple)?;
     if default_toolchain != inferred.to_string() {
         warn!("rustup will install the default toolchain as specified in the settings file,");
         warn!("instead of the one inferred from the default host tuple.");
@@ -786,28 +723,6 @@ fn pre_install_msg(no_modify_path: bool, process: &Process) -> Result<String> {
     }
 }
 
-fn current_install_opts(opts: &InstallOpts<'_>, process: &Process) -> String {
-    format!(
-        r"Current installation options:
-
-- `  `default host tuple: `{}`
-- `   `default toolchain: `{}`
-- `             `profile: `{}`
-- modify PATH variable: `{}`
-",
-        opts.default_host_tuple
-            .as_ref()
-            .map(TargetTuple::new)
-            .unwrap_or_else(|| TargetTuple::from_host_or_build(process)),
-        match &opts.default_toolchain {
-            Some(name) => name.to_string(),
-            None => "stable (default)".to_owned(),
-        },
-        opts.profile,
-        if !opts.no_modify_path { "yes" } else { "no" }
-    )
-}
-
 #[cfg(unix)]
 fn warn_if_default_linker_missing(process: &Process) {
     // Search for linker in PATH
@@ -998,66 +913,22 @@ fn check_proxy_sanity(process: &Process, components: &[&str], desc: &ToolchainDe
     Ok(())
 }
 
-async fn maybe_install_rust(opts: InstallOpts<'_>, cfg: &mut Cfg<'_>) -> Result<()> {
-    install_bins(cfg.process)?;
-
-    #[cfg(unix)]
-    unix::do_write_env_files(cfg.process)?;
-
-    if !opts.no_modify_path {
-        do_add_to_path(cfg.process)?;
-    }
-
-    // If RUSTUP_HOME is not set, make sure it exists
-    if cfg.process.var_os("RUSTUP_HOME").is_none() {
-        let home = cfg
-            .process
-            .home_dir()
-            .map(|p| p.join(".rustup"))
-            .ok_or_else(|| anyhow::anyhow!("could not find home dir to put .rustup in"))?;
-
-        fs::create_dir_all(home).context("unable to create ~/.rustup")?;
-    }
-
-    let (components, targets) = (opts.components, opts.targets);
-    let toolchain = opts.install(cfg)?;
-    if let Some(desc) = &toolchain {
-        let options = DistOptions::new(components, targets, desc, cfg.get_profile()?, true, cfg)?;
-        let status = if Toolchain::exists(cfg, &desc.into())? {
-            warn!("Updating existing toolchain, profile choice will be ignored");
-            // If we have a partial install we might not be able to read content here. We could:
-            // - fail and folk have to delete the partially present toolchain to recover
-            // - silently ignore it (and provide inconsistent metadata for reporting the install/update change)
-            // - delete the partial install and start over
-            // For now, we error.
-            let toolchain = DistributableToolchain::new(cfg, desc.clone())?;
-            InstallMethod::Dist(options.for_update(&toolchain, false))
-                .install(None)
-                .await?
-        } else {
-            DistributableToolchain::install(options).await?.status
-        };
-
-        check_proxy_sanity(cfg.process, components, desc)?;
-
-        cfg.set_default(Some(&desc.clone().into()))?;
-        writeln!(cfg.process.stdout().lock())?;
-        common::show_channel_update(cfg, PackageUpdate::Toolchain(desc.clone()), Ok(status))?;
-    }
-    Ok(())
-}
-
-pub(crate) fn uninstall(
-    no_prompt: bool,
-    no_modify_path: bool,
-    process: &Process,
-) -> Result<ExitCode> {
+/// Uninstall process:
+/// 1. Remove all installed toolchains.
+/// 2. Remove rustup home.
+/// 3. Remove all entries in `$CARGO_HOME` except `bin`.
+/// 4. Remove rustup tool links and binary.
+/// 5. Try to remove $CARGO_HOME/bin directory if it's empty.
+/// 6. Upon successfully removing $CARGO_HOME/bin, clean up $PATH.
+/// 7. Try to remove $CARGO_HOME directory if it's empty.
+pub(crate) fn uninstall(no_prompt: bool, no_modify_path: bool, cfg: &Cfg<'_>) -> Result<ExitCode> {
     if cfg!(feature = "no-self-update") {
         error!("self-uninstall is disabled for this build of rustup");
         error!("you should probably use your system package manager to uninstall rustup");
         return Ok(ExitCode::FAILURE);
     }
 
+    let process = cfg.process;
     let cargo_home = process.cargo_home()?;
 
     if !cargo_home.join(format!("bin/rustup{EXE_SUFFIX}")).exists() {
@@ -1081,6 +952,11 @@ pub(crate) fn uninstall(
         }
     }
 
+    info!("removing toolchains");
+    for toolchain in cfg.list_toolchains()? {
+        Toolchain::ensure_removed(cfg, toolchain.into())?;
+    }
+
     info!("removing rustup home");
 
     // Delete RUSTUP_HOME
@@ -1245,7 +1121,7 @@ pub(crate) async fn update(cfg: &Cfg<'_>) -> Result<ExitCode> {
                 PackageUpdate::Rustup,
                 Ok(UpdateStatus::Updated(version)),
             );
-            return run_update(&setup_path);
+            return run_update(&setup_path, cfg.process);
         }
         None => {
             let _ = common::show_channel_update(
@@ -1481,7 +1357,7 @@ mod tests {
                     .unwrap()
                     .resolve(&cfg.default_host_tuple().unwrap())
                     .unwrap(),
-                opts.install(&mut cfg)
+                opts.select_toolchain(&mut cfg)
                     .unwrap() // result
                     .unwrap() // option
             );
diff --git a/src/cli/self_update/msg.rs b/src/cli/self_update/msg.rs
new file mode 100644
index 0000000000..fecaafc695
--- /dev/null
+++ b/src/cli/self_update/msg.rs
@@ -0,0 +1,150 @@
+//! The big installation messages. These are macros because the first
+//! argument of format! needs to be a literal.
+
+macro_rules! pre_install_msg_template {
+    ($platform_msg:literal) => {
+        concat!(
+            r"
+# Welcome to Rust!
+
+This will download and install the official compiler for the Rust
+programming language, and its package manager, Cargo.
+
+Rustup metadata and toolchains will be installed into the Rustup
+home directory, located at:
+
+    {rustup_home}
+
+This can be modified with the RUSTUP_HOME environment variable.
+
+The Cargo home directory is located at:
+
+    {cargo_home}
+
+This can be modified with the CARGO_HOME environment variable.
+
+The `cargo`, `rustc`, `rustup` and other commands will be added to
+Cargo's bin directory, located at:
+
+    {cargo_home_bin}
+
+",
+            $platform_msg,
+            r#"
+
+You can uninstall at any time with `rustup self uninstall` and
+these changes will be reverted.
+"#
+        )
+    };
+}
+
+#[cfg(not(windows))]
+macro_rules! pre_install_msg_unix {
+    () => {
+        pre_install_msg_template!(
+            "This path will then be added to your `PATH` environment variable by
+modifying the profile file{plural} located at:
+
+{rcfiles}"
+        )
+    };
+}
+
+#[cfg(windows)]
+macro_rules! pre_install_msg_win {
+    () => {
+        pre_install_msg_template!(
+            r#"This path will then be added to your `PATH` environment variable by
+modifying the `PATH` registry key at `HKEY_CURRENT_USER\Environment`."#
+        )
+    };
+}
+
+macro_rules! pre_install_msg_no_modify_path {
+    () => {
+        pre_install_msg_template!(
+            "This path needs to be in your `PATH` environment variable,
+but will not be added automatically."
+        )
+    };
+}
+
+#[cfg(not(windows))]
+macro_rules! post_install_msg_unix {
+    () => {
+        r"# Rust is installed now. Great!
+
+To get started you may need to restart your current shell.
+This would reload your `PATH` environment variable to include
+Cargo's bin directory ({cargo_home}/bin).
+
+To configure your current shell, you need to source the
+corresponding `env` file under {cargo_home}.
+
+Consider running the right command for your shell (note the leading DOT):
+{source_env_lines}"
+    };
+}
+
+#[cfg(windows)]
+macro_rules! post_install_msg_win {
+    () => {
+        r"# Rust is installed now. Great!
+
+
+To get started you may need to restart your current shell.
+This would reload its `PATH` environment variable to include
+Cargo's bin directory ({cargo_home}\\bin).
+"
+    };
+}
+
+#[cfg(not(windows))]
+macro_rules! post_install_msg_unix_no_modify_path {
+    () => {
+        r"# Rust is installed now. Great!
+
+To get started you need Cargo's bin directory ({cargo_home}/bin) in your `PATH`
+environment variable. This has not been done automatically.
+
+To configure your current shell, you need to source
+the corresponding `env` file under {cargo_home}.
+
+Consider running the right command for your shell (note the leading DOT):
+{source_env_lines}"
+    };
+}
+
+#[cfg(windows)]
+macro_rules! post_install_msg_win_no_modify_path {
+    () => {
+        r"# Rust is installed now. Great!
+
+To get started you need Cargo's bin directory ({cargo_home}\\bin) in your `PATH`
+environment variable. This has not been done automatically.
+"
+    };
+}
+
+macro_rules! pre_uninstall_msg {
+    () => {
+        r"# Thanks for hacking in Rust!
+
+This will uninstall all Rust toolchains and data, and remove
+`{cargo_home}/bin` from your `PATH` environment variable.
+
+"
+    };
+}
+
+macro_rules! pre_uninstall_msg_no_modify_path {
+    () => {
+        r"# Thanks for hacking in Rust!
+
+This will uninstall all Rust toolchains and data.
+Your `PATH` environment variable will not be touched.
+
+"
+    };
+}
diff --git a/src/cli/self_update/unix.rs b/src/cli/self_update/unix.rs
index e4e236e2bc..b099534354 100644
--- a/src/cli/self_update/unix.rs
+++ b/src/cli/self_update/unix.rs
@@ -61,10 +61,7 @@ pub(crate) fn do_remove_from_path(process: &Process) -> Result<()> {
             let file = utils::read_file("rcfile", rc)?;
             let file_bytes = file.into_bytes();
             // FIXME: This is whitespace sensitive where it should not be.
-            if let Some(idx) = file_bytes
-                .windows(source_bytes.len())
-                .position(|w| w == source_bytes.as_slice())
-            {
+            if let Some(idx) = find_exact_line(&file_bytes, &source_bytes) {
                 // Here we rewrite the file without the offending line.
                 let mut new_bytes = file_bytes[..idx].to_vec();
                 new_bytes.extend(&file_bytes[idx + source_bytes.len()..]);
@@ -125,7 +122,7 @@ pub(crate) fn do_write_env_files(process: &Process) -> Result<()> {
 
 /// Tell the upgrader to replace the rustup bins, then delete
 /// itself.
-pub(crate) fn run_update(setup_path: &Path) -> Result<utils::ExitCode> {
+pub(crate) fn run_update(setup_path: &Path, _process: &Process) -> Result<utils::ExitCode> {
     let status = Command::new(setup_path)
         .arg("--self-replace")
         .status()
@@ -153,10 +150,7 @@ fn remove_legacy_source_command(source_cmd: String, process: &Process) -> Result
         let file = utils::read_file("rcfile", &rc)?;
         let file_bytes = file.into_bytes();
         // FIXME: This is whitespace sensitive where it should not be.
-        if let Some(idx) = file_bytes
-            .windows(cmd_bytes.len())
-            .position(|w| w == cmd_bytes.as_slice())
-        {
+        if let Some(idx) = find_exact_line(&file_bytes, &cmd_bytes) {
             // Here we rewrite the file without the offending line.
             let mut new_bytes = file_bytes[..idx].to_vec();
             new_bytes.extend(&file_bytes[idx + cmd_bytes.len()..]);
@@ -167,6 +161,16 @@ fn remove_legacy_source_command(source_cmd: String, process: &Process) -> Result
     Ok(())
 }
 
+fn find_exact_line(file: &[u8], line: &[u8]) -> Option<usize> {
+    // The trailing newline enforces the end boundary; check the start boundary here.
+    assert!(line.ends_with(b"\n"));
+    file.windows(line.len())
+        .enumerate()
+        .find_map(|(idx, candidate)| {
+            (candidate == line && (idx == 0 || file[idx - 1] == b'\n')).then_some(idx)
+        })
+}
+
 fn remove_legacy_paths(process: &Process) -> Result<()> {
     // Before the work to support more kinds of shells, which was released in
     // version 1.23.0 of Rustup, we always inserted this line instead, which is
diff --git a/src/cli/self_update/windows.rs b/src/cli/self_update/windows.rs
index fc3f9d0648..51acf1f7e0 100644
--- a/src/cli/self_update/windows.rs
+++ b/src/cli/self_update/windows.rs
@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::env::{consts::EXE_SUFFIX, split_paths};
 use std::ffi::{OsStr, OsString};
 use std::fmt;
@@ -5,8 +6,6 @@ use std::io::Write;
 use std::os::windows::ffi::OsStrExt;
 use std::path::Path;
 use std::process::Command;
-#[cfg(any(test, feature = "test"))]
-use std::sync::{LockResult, Mutex, MutexGuard};
 
 use anyhow::{Context, Result, anyhow};
 use tracing::{info, warn};
@@ -20,9 +19,7 @@ use super::super::errors::CliError;
 use super::common;
 use super::{InstallOpts, install_bins, report_error};
 use crate::cli::markdown::md;
-use crate::config::Cfg;
 use crate::dist::TargetTuple;
-use crate::dist::download::DownloadCfg;
 use crate::download::download_file;
 use crate::process::{ColorableTerminal, Process};
 use crate::utils;
@@ -92,35 +89,36 @@ pub(crate) fn choose_vs_install(process: &Process) -> Result<Option<VsInstallPla
 pub(super) async fn maybe_install_msvc(
     term: &mut ColorableTerminal,
     no_prompt: bool,
+    quiet: bool,
     opts: &InstallOpts<'_>,
-    cfg: &Cfg<'_>,
+    process: &Process,
 ) -> Result<()> {
-    let Some(plan) = do_msvc_check(opts, cfg.process) else {
+    let Some(plan) = do_msvc_check(opts, process) else {
         return Ok(());
     };
 
     if no_prompt {
         warn!("installing msvc toolchain without its prerequisites");
-    } else if !cfg.quiet && plan == VsInstallPlan::Automatic {
+    } else if !quiet && plan == VsInstallPlan::Automatic {
         md(term, MSVC_AUTO_INSTALL_MESSAGE);
-        match choose_vs_install(cfg.process)? {
+        match choose_vs_install(process)? {
             Some(VsInstallPlan::Automatic) => {
-                match try_install_msvc(opts, cfg).await {
+                match try_install_msvc(opts, process).await {
                     Err(e) => {
                         // Make sure the console doesn't exit before the user can
                         // see the error and give the option to continue anyway.
-                        report_error(&e, cfg.process);
-                        if !common::question_bool("\nContinue?", false, cfg.process)? {
+                        report_error(&e, process);
+                        if !common::question_bool("\nContinue?", false, process)? {
                             info!("aborting installation");
                         }
                     }
-                    Ok(ContinueInstall::No) => ensure_prompt(cfg.process)?,
+                    Ok(ContinueInstall::No) => ensure_prompt(process)?,
                     _ => {}
                 }
             }
             Some(VsInstallPlan::Manual) => {
                 md(term, MSVC_MANUAL_INSTALL_MESSAGE);
-                if !common::question_bool("\nContinue?", false, cfg.process)? {
+                if !common::question_bool("\nContinue?", false, process)? {
                     info!("aborting installation");
                 }
             }
@@ -129,7 +127,7 @@ pub(super) async fn maybe_install_msvc(
     } else {
         md(term, MSVC_MESSAGE);
         md(term, MSVC_MANUAL_INSTALL_MESSAGE);
-        if !common::question_bool("\nContinue?", false, cfg.process)? {
+        if !common::question_bool("\nContinue?", false, process)? {
             info!("aborting installation");
         }
     }
@@ -260,7 +258,7 @@ pub(crate) enum ContinueInstall {
 /// but the rustup install should not be continued at this time.
 pub(crate) async fn try_install_msvc(
     opts: &InstallOpts<'_>,
-    cfg: &Cfg<'_>,
+    process: &Process,
 ) -> Result<ContinueInstall> {
     // download the installer
     let visual_studio_url = utils::parse_url("https://aka.ms/vs/17/release/vs_community.exe")?;
@@ -271,16 +269,8 @@ pub(crate) async fn try_install_msvc(
         .context("error creating temp directory")?;
 
     let visual_studio = tempdir.path().join("vs_setup.exe");
-    let dl_cfg = DownloadCfg::new(cfg);
     info!("downloading Visual Studio installer");
-    download_file(
-        &visual_studio_url,
-        &visual_studio,
-        None,
-        None,
-        dl_cfg.process,
-    )
-    .await?;
+    download_file(&visual_studio_url, &visual_studio, None, None, process).await?;
 
     // Run the installer. Arguments are documented at:
     // https://docs.microsoft.com/en-us/visualstudio/install/use-command-line-parameters-to-install-visual-studio
@@ -295,7 +285,7 @@ pub(crate) async fn try_install_msvc(
 
     // It's possible an earlier or later version of the Windows SDK has been
     // installed separately from Visual Studio so installing it can be skipped.
-    if !has_windows_sdk_libs(cfg.process) {
+    if !has_windows_sdk_libs(process) {
         cmd.args([
             "--add",
             "Microsoft.VisualStudio.Component.Windows11SDK.26100",
@@ -328,8 +318,8 @@ pub(crate) async fn try_install_msvc(
                 // It's possible that the installer returned a non-zero exit code
                 // even though the required components were successfully installed.
                 // In that case we warn about the error but continue on.
-                let have_msvc = do_msvc_check(opts, cfg.process).is_none();
-                let has_libs = has_windows_sdk_libs(cfg.process);
+                let have_msvc = do_msvc_check(opts, process).is_none();
+                let has_libs = has_windows_sdk_libs(process);
                 if have_msvc && has_libs {
                     warn!("Visual Studio is installed but a problem occurred during installation");
                     warn!("{}", err);
@@ -454,11 +444,11 @@ pub(crate) fn wait_for_parent() -> Result<()> {
 
 pub(crate) fn do_add_to_path(process: &Process) -> Result<()> {
     let new_path = _with_path_cargo_home_bin(_add_to_path, process)?;
-    _apply_new_path(new_path)?;
-    do_add_to_programs(process)
+    _apply_new_path(new_path, process)?;
+    add_uninstall_registry_entry(process)
 }
 
-fn _apply_new_path(new_path: Option<HSTRING>) -> Result<()> {
+fn _apply_new_path(new_path: Option<HSTRING>, process: &Process) -> Result<()> {
     use std::ptr;
     use windows_sys::Win32::Foundation::{LPARAM, WPARAM};
     use windows_sys::Win32::UI::WindowsAndMessaging::{
@@ -469,7 +459,7 @@ fn _apply_new_path(new_path: Option<HSTRING>) -> Result<()> {
         return Ok(()); // No need to set the path
     };
 
-    let environment = CURRENT_USER.create("Environment")?;
+    let environment = process.registry_environment_key()?;
 
     if new_path.is_empty() {
         environment.remove_value("PATH")?;
@@ -497,9 +487,9 @@ fn _apply_new_path(new_path: Option<HSTRING>) -> Result<()> {
 // Get the windows PATH variable out of the registry as a String. If
 // this returns None then the PATH variable is not a string and we
 // should not mess with it.
-fn get_windows_path_var() -> Result<Option<HSTRING>> {
-    let environment = CURRENT_USER
-        .create("Environment")
+fn get_windows_path_var(process: &Process) -> Result<Option<HSTRING>> {
+    let environment = process
+        .registry_environment_key()
         .context("Failed opening Environment key")?;
 
     let reg_value = environment.get_hstring("PATH");
@@ -563,7 +553,7 @@ fn _with_path_cargo_home_bin<F>(f: F, process: &Process) -> Result<Option<HSTRIN
 where
     F: FnOnce(HSTRING, HSTRING) -> Option<HSTRING>,
 {
-    let windows_path = get_windows_path_var()?;
+    let windows_path = get_windows_path_var(process)?;
     let mut path_str = process.cargo_home()?;
     path_str.push("bin");
     Ok(windows_path.and_then(|old_path| f(old_path, HSTRING::from(path_str.as_path()))))
@@ -571,28 +561,58 @@ where
 
 pub(crate) fn do_remove_from_path(process: &Process) -> Result<()> {
     let new_path = _with_path_cargo_home_bin(_remove_from_path, process)?;
-    _apply_new_path(new_path)?;
-    do_remove_from_programs()
+    _apply_new_path(new_path, process)?;
+    remove_uninstall_registry_entry(process)
 }
 
 const RUSTUP_UNINSTALL_ENTRY: &str = r"Software\Microsoft\Windows\CurrentVersion\Uninstall\Rustup";
 
-fn rustup_uninstall_reg_key() -> Result<Key> {
-    CURRENT_USER
-        .create(RUSTUP_UNINSTALL_ENTRY)
+impl Process {
+    fn registry_sub_key_path<'a>(&self, sub_key: &'a str) -> Cow<'a, str> {
+        #[cfg(any(test, feature = "test"))]
+        if let Ok(test_id) = self.var(RUSTUP_REGISTRY_TEST_ID) {
+            return Cow::Owned(format!(r"RustupTest-{test_id}\{sub_key}"));
+        }
+
+        Cow::Borrowed(sub_key)
+    }
+
+    fn registry_key(&self, sub_key: &str, parent: &Key) -> windows_registry::Result<Key> {
+        let mut options = parent.options();
+        options.read().write().create();
+
+        #[cfg(any(test, feature = "test"))]
+        if self.var(RUSTUP_REGISTRY_TEST_ID).is_ok() {
+            options.volatile();
+        }
+
+        options.open(self.registry_sub_key_path(sub_key))
+    }
+
+    fn registry_environment_key(&self) -> windows_registry::Result<Key> {
+        self.registry_key("Environment", CURRENT_USER)
+    }
+}
+
+fn rustup_uninstall_registry_key(process: &Process) -> Result<Key> {
+    process
+        .registry_key(RUSTUP_UNINSTALL_ENTRY, CURRENT_USER)
         .context("Failed creating uninstall key")
 }
 
-pub(crate) fn do_update_programs_display_version(version: &str) -> Result<()> {
-    rustup_uninstall_reg_key()?
+pub(crate) fn update_uninstall_registry_display_version(
+    version: &str,
+    process: &Process,
+) -> Result<()> {
+    rustup_uninstall_registry_key(process)?
         .set_string("DisplayVersion", version)
         .context("Failed to set `DisplayVersion`")
 }
 
-pub(crate) fn do_add_to_programs(process: &Process) -> Result<()> {
+pub(crate) fn add_uninstall_registry_entry(process: &Process) -> Result<()> {
     use std::path::PathBuf;
 
-    let key = rustup_uninstall_reg_key()?;
+    let key = rustup_uninstall_registry_key(process)?;
 
     // Don't overwrite registry if Rustup is already installed
     let prev = key.get_hstring("UninstallString");
@@ -614,20 +634,20 @@ pub(crate) fn do_add_to_programs(process: &Process) -> Result<()> {
         .context("Failed to set `UninstallString`")?;
     key.set_string("DisplayName", "Rustup: the Rust toolchain installer")
         .context("Failed to set `DisplayName`")?;
-    do_update_programs_display_version(env!("CARGO_PKG_VERSION"))?;
+    update_uninstall_registry_display_version(env!("CARGO_PKG_VERSION"), process)?;
 
     Ok(())
 }
 
-pub(crate) fn do_remove_from_programs() -> Result<()> {
-    match CURRENT_USER.remove_tree(RUSTUP_UNINSTALL_ENTRY) {
+pub(crate) fn remove_uninstall_registry_entry(process: &Process) -> Result<()> {
+    match CURRENT_USER.remove_tree(process.registry_sub_key_path(RUSTUP_UNINSTALL_ENTRY)) {
         Ok(()) => Ok(()),
         Err(e) if e.code() == HRESULT::from_win32(ERROR_FILE_NOT_FOUND) => Ok(()),
         Err(e) => Err(anyhow!(e)),
     }
 }
 
-pub(crate) fn run_update(setup_path: &Path) -> Result<utils::ExitCode> {
+pub(crate) fn run_update(setup_path: &Path, process: &Process) -> Result<utils::ExitCode> {
     Command::new(setup_path)
         .arg("--self-replace")
         .spawn()
@@ -637,7 +657,7 @@ pub(crate) fn run_update(setup_path: &Path) -> Result<utils::ExitCode> {
         warn!("failed to get the new rustup version in order to update `DisplayVersion`");
         return Ok(utils::ExitCode(1));
     };
-    do_update_programs_display_version(&version)?;
+    update_uninstall_registry_display_version(&version, process)?;
 
     Ok(utils::ExitCode(0))
 }
@@ -754,39 +774,15 @@ pub(crate) fn delete_rustup_and_cargo_home(process: &Process) -> Result<()> {
     Ok(())
 }
 
+/// Environment variable carrying the per-test registry ID.
 #[cfg(any(test, feature = "test"))]
-pub fn get_path() -> Result<Option<Value>> {
-    USER_PATH.get()
-}
+pub const RUSTUP_REGISTRY_TEST_ID: &str = "RUSTUP_REGISTRY_TEST_ID";
 
 #[cfg(any(test, feature = "test"))]
-pub struct RegistryGuard<'a> {
-    _locked: LockResult<MutexGuard<'a, ()>>,
-    id: &'static RegistryValueId,
-    prev: Option<Value>,
+pub fn get_path(test_id: &str) -> Result<Option<Value>> {
+    USER_PATH.get(test_id, CURRENT_USER)
 }
 
-#[cfg(any(test, feature = "test"))]
-impl RegistryGuard<'_> {
-    pub fn new(id: &'static RegistryValueId) -> Result<Self> {
-        Ok(Self {
-            _locked: REGISTRY_LOCK.lock(),
-            id,
-            prev: id.get()?,
-        })
-    }
-}
-
-#[cfg(any(test, feature = "test"))]
-impl Drop for RegistryGuard<'_> {
-    fn drop(&mut self) {
-        self.id.set(self.prev.as_ref()).unwrap();
-    }
-}
-
-#[cfg(any(test, feature = "test"))]
-static REGISTRY_LOCK: Mutex<()> = Mutex::new(());
-
 #[cfg(any(test, feature = "test"))]
 pub const USER_PATH: RegistryValueId = RegistryValueId {
     sub_key: "Environment",
@@ -801,8 +797,10 @@ pub struct RegistryValueId {
 
 #[cfg(any(test, feature = "test"))]
 impl RegistryValueId {
-    pub fn get(&self) -> Result<Option<Value>> {
-        let sub_key = CURRENT_USER.create(self.sub_key)?;
+    pub fn get(&self, test_id: &str, parent: &Key) -> Result<Option<Value>> {
+        let mut options = parent.options();
+        options.read().write().create().volatile();
+        let sub_key = options.open(format!(r"RustupTest-{test_id}\{}", self.sub_key))?;
         match sub_key.get_value(self.value_name) {
             Ok(val) => Ok(Some(val)),
             Err(e) if e.code() == HRESULT::from_win32(ERROR_FILE_NOT_FOUND) => Ok(None),
@@ -810,23 +808,109 @@ impl RegistryValueId {
         }
     }
 
-    pub fn set(&self, new: Option<&Value>) -> Result<()> {
-        let sub_key = CURRENT_USER.create(self.sub_key)?;
+    pub fn set(&self, new: Option<&Value>, test_id: &str, parent: &Key) -> Result<()> {
+        let mut options = parent.options();
+        options.read().write().create().volatile();
+        let sub_key = options.open(format!(r"RustupTest-{test_id}\{}", self.sub_key))?;
         match new {
             Some(new) => Ok(sub_key.set_value(self.value_name, new)?),
-            None => Ok(sub_key.remove_value(self.value_name)?),
+            None => match sub_key.remove_value(self.value_name) {
+                Ok(()) => Ok(()),
+                Err(e) if e.code() == HRESULT::from_win32(ERROR_FILE_NOT_FOUND) => Ok(()),
+                Err(e) => Err(e.into()),
+            },
         }
     }
 }
 
 #[cfg(test)]
 mod tests {
+    use std::collections::HashMap;
     use std::os::windows::ffi::OsStringExt;
 
     use windows_registry::Type;
 
     use super::*;
     use crate::process::TestProcess;
+    use crate::test::test_id;
+
+    fn test_process(test_id: &str) -> TestProcess {
+        let vars: HashMap<String, String> = [
+            ("HOME".to_string(), "/unused".to_string()),
+            (RUSTUP_REGISTRY_TEST_ID.to_string(), test_id.to_owned()),
+        ]
+        .into_iter()
+        .collect();
+        TestProcess::with_vars(vars)
+    }
+
+    fn clear_path(environment: &Key) {
+        match environment.remove_value("PATH") {
+            Ok(()) => {}
+            Err(e) if e.code() == HRESULT::from_win32(ERROR_FILE_NOT_FOUND) => {}
+            Err(e) => panic!("failed to clear PATH: {e}"),
+        }
+    }
+
+    #[test]
+    fn windows_registry_isolated_per_test_id() {
+        let first_id = test_id();
+        let second_id = test_id();
+        let first = test_process(&first_id);
+        let second = test_process(&second_id);
+        let first_value = Value::from("first");
+        let second_value = Value::from("second");
+
+        USER_PATH
+            .set(Some(&first_value), &first_id, CURRENT_USER)
+            .unwrap();
+        USER_PATH
+            .set(Some(&second_value), &second_id, CURRENT_USER)
+            .unwrap();
+
+        assert_eq!(
+            first
+                .process
+                .registry_environment_key()
+                .unwrap()
+                .get_hstring("PATH")
+                .unwrap(),
+            HSTRING::from("first")
+        );
+        assert_eq!(
+            second
+                .process
+                .registry_environment_key()
+                .unwrap()
+                .get_hstring("PATH")
+                .unwrap(),
+            HSTRING::from("second")
+        );
+
+        let programs_version = RegistryValueId {
+            sub_key: RUSTUP_UNINSTALL_ENTRY,
+            value_name: "DisplayVersion",
+        };
+        programs_version
+            .set(Some(&first_value), &first_id, CURRENT_USER)
+            .unwrap();
+        assert_eq!(
+            programs_version.get(&first_id, CURRENT_USER).unwrap(),
+            Some(first_value)
+        );
+        assert_eq!(
+            programs_version.get(&second_id, CURRENT_USER).unwrap(),
+            None
+        );
+    }
+
+    #[test]
+    fn windows_registry_cleanup_is_idempotent() {
+        let test_id = test_id();
+        let tp = test_process(&test_id);
+
+        remove_uninstall_registry_entry(&tp.process).unwrap();
+    }
 
     #[test]
     fn windows_install_does_not_add_path_twice() {
@@ -864,16 +948,20 @@ mod tests {
     #[test]
     fn windows_path_regkey_type() {
         // per issue #261, setting PATH should use REG_EXPAND_SZ.
-        let _guard = RegistryGuard::new(&USER_PATH);
-        let environment = CURRENT_USER.create("Environment").unwrap();
-        environment.remove_value("PATH").unwrap();
+        let test_id = test_id();
+        let tp = test_process(&test_id);
+        let environment = tp.process.registry_environment_key().unwrap();
+        clear_path(&environment);
 
         {
             // Can't compare the Results as Eq isn't derived; thanks error-chain.
             #![allow(clippy::unit_cmp)]
-            assert_eq!((), _apply_new_path(Some(HSTRING::from("foo"))).unwrap());
+            assert_eq!(
+                (),
+                _apply_new_path(Some(HSTRING::from("foo")), &tp.process).unwrap()
+            );
         }
-        let environment = CURRENT_USER.create("Environment").unwrap();
+        let environment = tp.process.registry_environment_key().unwrap();
         let path = environment.get_value("PATH").unwrap();
         let path_hstring = environment.get_hstring("PATH").unwrap();
         assert_eq!(path.ty(), Type::ExpandString);
@@ -884,8 +972,9 @@ mod tests {
     fn windows_path_delete_key_when_empty() {
         // during uninstall the PATH key may end up empty; if so we should
         // delete it.
-        let _guard = RegistryGuard::new(&USER_PATH);
-        let environment = CURRENT_USER.create("Environment").unwrap();
+        let test_id = test_id();
+        let tp = test_process(&test_id);
+        let environment = tp.process.registry_environment_key().unwrap();
         environment
             .set_expand_hstring("PATH", &HSTRING::from("foo"))
             .unwrap();
@@ -893,7 +982,10 @@ mod tests {
         {
             // Can't compare the Results as Eq isn't derived; thanks error-chain.
             #![allow(clippy::unit_cmp)]
-            assert_eq!((), _apply_new_path(Some(HSTRING::new())).unwrap());
+            assert_eq!(
+                (),
+                _apply_new_path(Some(HSTRING::new()), &tp.process).unwrap()
+            );
         }
         let reg_value = environment.get_value("PATH");
         match reg_value {
@@ -905,16 +997,11 @@ mod tests {
 
     #[test]
     fn windows_doesnt_mess_with_a_non_string_path() {
+        let test_id = test_id();
         // This writes an error, so we want a sink for it.
-        let tp = TestProcess::with_vars(
-            [("HOME".to_string(), "/unused".to_string())]
-                .iter()
-                .cloned()
-                .collect(),
-        );
+        let tp = test_process(&test_id);
 
-        let _guard = RegistryGuard::new(&USER_PATH);
-        let environment = CURRENT_USER.create("Environment").unwrap();
+        let environment = tp.process.registry_environment_key().unwrap();
         environment
             .set_bytes("PATH", Type::Bytes, &[0x12, 0x34])
             .unwrap();
@@ -934,11 +1021,15 @@ mod tests {
     #[test]
     fn windows_treat_missing_path_as_empty() {
         // during install the PATH key may be missing; treat it as empty
-        let _guard = RegistryGuard::new(&USER_PATH);
-        let environment = CURRENT_USER.create("Environment").unwrap();
-        environment.remove_value("PATH").unwrap();
+        let test_id = test_id();
+        let tp = test_process(&test_id);
+        let environment = tp.process.registry_environment_key().unwrap();
+        clear_path(&environment);
 
-        assert_eq!(Some(HSTRING::new()), get_windows_path_var().unwrap());
+        assert_eq!(
+            Some(HSTRING::new()),
+            get_windows_path_var(&tp.process).unwrap()
+        );
     }
 
     #[test]
diff --git a/src/cli/setup_mode.rs b/src/cli/setup_mode.rs
index e0bc08df60..f0eeb4e6b8 100644
--- a/src/cli/setup_mode.rs
+++ b/src/cli/setup_mode.rs
@@ -10,7 +10,6 @@ use crate::{
         common::{self, update_console_filter},
         self_update::{self, InstallOpts},
     },
-    config::Cfg,
     dist::Profile,
     process::Process,
     toolchain::MaybeOfficialToolchainName,
@@ -129,7 +128,5 @@ pub async fn main(
         components: &component.iter().map(|s| &**s).collect::<Vec<_>>(),
         targets: &target.iter().map(|s| &**s).collect::<Vec<_>>(),
     };
-
-    let mut cfg = Cfg::from_env(current_dir, quiet, true, process)?;
-    self_update::install(no_prompt, opts, &mut cfg).await
+    opts.install(current_dir, no_prompt, quiet, process).await
 }
diff --git a/src/config.rs b/src/config.rs
index 30c3b73e6b..511b6de7e8 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -197,7 +197,7 @@ impl OverrideCfg {
     fn from_file(cfg: &Cfg<'_>, file: OverrideFile) -> Result<Self> {
         let toolchain_name = match (file.toolchain.channel, file.toolchain.path) {
             (Some(name), None) => {
-                ResolvableToolchainName::try_from(name)?.resolve(&cfg.default_host_tuple()?)?
+                ResolvableToolchainName::from_str(&name)?.resolve(&cfg.default_host_tuple()?)?
             }
             (None, Some(path)) => {
                 if file.toolchain.targets.is_some()
@@ -253,7 +253,7 @@ impl OverrideCfg {
         match self {
             Self::PathBased(path_based_name) => path_based_name.into(),
             Self::Custom(custom_name) => custom_name.into(),
-            Self::Official { toolchain, .. } => (&toolchain).into(),
+            Self::Official { toolchain, .. } => toolchain.into(),
         }
     }
 }
@@ -353,8 +353,8 @@ impl<'a> Cfg<'a> {
         // Figure out default_host_tuple before Config is populated
         let default_host = settings_file.with(|s| Ok(default_host_tuple(s, process)))?;
         // Environment override
-        let env_override = match process.var_opt("RUSTUP_TOOLCHAIN")? {
-            Some(tc) => Some(ResolvableLocalToolchainName::try_from(tc)?.resolve(&default_host)?),
+        let env_override = match &process.var_opt("RUSTUP_TOOLCHAIN")? {
+            Some(tc) => Some(ResolvableLocalToolchainName::from_str(tc)?.resolve(&default_host)?),
             None => None,
         };
 
@@ -382,7 +382,7 @@ impl<'a> Cfg<'a> {
         // Run some basic checks against the constructed configuration
         // For now, that means simply checking that 'stable' can resolve
         // for the current configuration.
-        ResolvableToolchainName::try_from("stable")?.resolve(
+        ResolvableToolchainName::from_str("stable")?.resolve(
             &cfg.default_host_tuple()
                 .context("Unable parse configuration")?,
         )?;
@@ -637,7 +637,7 @@ impl<'a> Cfg<'a> {
                 // However, settings.toml could conceivably be hand edited to
                 // have an unresolved name. I'm just preserving pre-existing
                 // behaviour by choosing ResolvableToolchainName here.
-                let toolchain_name = ResolvableToolchainName::try_from(name)?
+                let toolchain_name = ResolvableToolchainName::from_str(&name)?
                     .resolve(&default_host_tuple(settings, self.process))?;
                 let override_cfg = toolchain_name.into();
                 return Ok(Some((override_cfg, source)));
@@ -689,7 +689,7 @@ impl<'a> Cfg<'a> {
                         }
                     })?;
                 if let Some(toolchain_name_str) = &override_file.toolchain.channel {
-                    let toolchain_name = ResolvableToolchainName::try_from(
+                    let toolchain_name = ResolvableToolchainName::from_str(
                         toolchain_name_str.as_str(),
                     )
                     .map_err(|_| {
@@ -707,7 +707,7 @@ impl<'a> Cfg<'a> {
                         // Permit fully qualified names IFF the toolchain is installed. TODO(robertc): consider
                         // disabling this and backing out https://github.com/rust-lang/rustup/pull/2141 (but provide
                         // the base name in the error to help users)
-                        let resolved_name = &ToolchainName::try_from(toolchain_name_str.as_str())?;
+                        let resolved_name = &ToolchainName::from_str(toolchain_name_str)?;
                         if !self.list_toolchains()?.iter().any(|s| s == resolved_name) {
                             return Err(anyhow!(format!("target tuple in channel name '{name}'")));
                         }
@@ -907,7 +907,7 @@ impl<'a> Cfg<'a> {
             user_opt
         }?;
         toolchain_maybe_str
-            .map(ResolvableToolchainName::try_from)
+            .map(|s| ResolvableToolchainName::from_str(&s))
             .transpose()?
             .map(|t| t.resolve(&self.default_host_tuple()?))
             .transpose()
@@ -928,7 +928,7 @@ impl<'a> Cfg<'a> {
                 .filter_map(io::Result::ok)
                 .filter(|e| e.file_type().map(|f| !f.is_file()).unwrap_or(false))
                 .filter_map(|e| e.file_name().into_string().ok())
-                .filter_map(|n| ToolchainName::try_from(n).ok())
+                .filter_map(|n| ToolchainName::from_str(&n).ok())
                 .collect();
 
             toolchains.sort();
@@ -1051,7 +1051,7 @@ impl Debug for Cfg<'_> {
     }
 }
 
-fn default_host_tuple(s: &Settings, process: &Process) -> TargetTuple {
+pub(crate) fn default_host_tuple(s: &Settings, process: &Process) -> TargetTuple {
     s.default_host_tuple
         .as_ref()
         .map(TargetTuple::new)
diff --git a/src/dist/manifestation.rs b/src/dist/manifestation.rs
index 469d830910..9bb2467e52 100644
--- a/src/dist/manifestation.rs
+++ b/src/dist/manifestation.rs
@@ -29,14 +29,13 @@ use crate::{
         config::Config,
         download::{DownloadCfg, DownloadStatus, File},
         manifest::{Component, CompressionKind, HashedBinary, Manifest},
-        prefix::InstallPrefix,
+        prefix::{DIST_MANIFEST, InstallPrefix},
         temp,
     },
     errors::RustupError,
     utils,
 };
 
-pub(crate) const DIST_MANIFEST: &str = "multirust-channel-manifest.toml";
 pub(crate) const CONFIG_FILE: &str = "multirust-config.toml";
 
 #[derive(Debug)]
@@ -396,8 +395,7 @@ impl Manifestation {
     #[tracing::instrument(level = "trace")]
     pub fn load_manifest(&self) -> Result<Option<Manifest>> {
         let prefix = self.installation.prefix();
-        let old_manifest_path = prefix.manifest_file(DIST_MANIFEST);
-        if utils::path_exists(&old_manifest_path) {
+        if let Some(old_manifest_path) = prefix.dist_manifest() {
             let manifest_str = utils::read_file("installed manifest", &old_manifest_path)?;
             Ok(Some(Manifest::parse(&manifest_str).with_context(|| {
                 RustupError::ParsingFile {
diff --git a/src/dist/mod.rs b/src/dist/mod.rs
index d74afa014c..090941cf9c 100644
--- a/src/dist/mod.rs
+++ b/src/dist/mod.rs
@@ -608,6 +608,7 @@ impl TargetTuple {
                 (b"Linux", b"loongarch64") => Some(TUPLE_LOONGARCH64_UNKNOWN_LINUX),
                 (b"Linux", b"ppc64") => Some(TUPLE_POWERPC64_UNKNOWN_LINUX),
                 (b"Linux", b"ppc64le") => Some(TUPLE_POWERPC64LE_UNKNOWN_LINUX),
+                (b"Linux", b"riscv64") => Some(TUPLE_RISCV64GC_UNKNOWN_LINUX),
                 (b"Darwin", b"x86_64") => Some("x86_64-apple-darwin"),
                 (b"Darwin", b"i686") => Some("i686-apple-darwin"),
                 (b"FreeBSD", b"x86_64") => Some("x86_64-unknown-freebsd"),
@@ -712,6 +713,10 @@ const TUPLE_POWERPC64_UNKNOWN_LINUX: &str = "powerpc64-unknown-linux-musl";
 const TUPLE_POWERPC64LE_UNKNOWN_LINUX: &str = "powerpc64le-unknown-linux-gnu";
 #[cfg(all(not(windows), target_env = "musl"))]
 const TUPLE_POWERPC64LE_UNKNOWN_LINUX: &str = "powerpc64le-unknown-linux-musl";
+#[cfg(all(not(windows), not(target_env = "musl")))]
+const TUPLE_RISCV64GC_UNKNOWN_LINUX: &str = "riscv64gc-unknown-linux-gnu";
+#[cfg(all(not(windows), target_env = "musl"))]
+const TUPLE_RISCV64GC_UNKNOWN_LINUX: &str = "riscv64gc-unknown-linux-musl";
 
 // MIPS platforms don't indicate endianness in uname, however binaries only
 // run on boxes with the same endianness, as expected.
@@ -1125,10 +1130,9 @@ async fn try_update_from_dist_(
     } else {
         download
             .dl_v2_manifest(
-                // Even if manifest has not changed, we must continue to install requested components.
-                // So if components or targets is not empty, we skip passing `update_hash` so that
-                // we essentially degenerate to `rustup component add` / `rustup target add`
-                if components.is_empty() && targets.is_empty() {
+                // Skip the update hash when the installed manifest is missing or when components
+                // or targets were requested, since either case still requires the channel manifest.
+                if prefix.dist_manifest().is_some() && components.is_empty() && targets.is_empty() {
                     Some(update_hash)
                 } else {
                     None
diff --git a/src/dist/prefix.rs b/src/dist/prefix.rs
index 9b71118017..c0217bfb86 100644
--- a/src/dist/prefix.rs
+++ b/src/dist/prefix.rs
@@ -11,6 +11,7 @@ const REL_MANIFEST_DIR: &str = match std::path::MAIN_SEPARATOR {
 };
 
 static V1_COMMON_COMPONENT_LIST: &[&str] = &["cargo", "rustc", "rust-docs"];
+pub(crate) const DIST_MANIFEST: &str = "multirust-channel-manifest.toml";
 
 #[derive(Clone, Debug)]
 pub struct InstallPrefix {
@@ -37,6 +38,11 @@ impl InstallPrefix {
         path
     }
 
+    pub(crate) fn dist_manifest(&self) -> Option<PathBuf> {
+        let path = self.manifest_file(DIST_MANIFEST);
+        utils::path_exists(&path).then_some(path)
+    }
+
     pub(crate) fn rel_manifest_file(&self, name: &str) -> PathBuf {
         let mut path = PathBuf::from(REL_MANIFEST_DIR);
         path.push(name);
diff --git a/src/dist/target_tuple/known.rs b/src/dist/target_tuple/known.rs
index b034a77211..6f46fbfb02 100644
--- a/src/dist/target_tuple/known.rs
+++ b/src/dist/target_tuple/known.rs
@@ -54,6 +54,7 @@ pub static LIST_ARCHS: &[&str] = &[
     "riscv32imac",
     "riscv32imafc",
     "riscv32imc",
+    "riscv32imfc",
     "riscv64",
     "riscv64a23",
     "riscv64gc",
@@ -108,9 +109,11 @@ pub static LIST_OSES: &[&str] = &[
     "nuttx-eabi",
     "nuttx-eabihf",
     "nvidia-cuda",
+    "oe-linux",
     "openwrt-linux",
     "pc-cygwin",
     "pc-nto",
+    "pc-qnx",
     "pc-solaris",
     "pc-windows",
     "risc0-zkvm",
@@ -138,6 +141,7 @@ pub static LIST_OSES: &[&str] = &[
     "unknown-nto",
     "unknown-nuttx",
     "unknown-openbsd",
+    "unknown-qnx",
     "unknown-qurt",
     "unknown-redox",
     "unknown-teeos",
@@ -187,10 +191,10 @@ pub static LIST_ENVS: &[&str] = &[
     "newlibeabihf",
     "none",
     "ohos",
+    "pauthtest",
     "qnx700",
     "qnx710",
     "qnx710_iosock",
-    "qnx800",
     "sgx",
     "sim",
     "softfloat",
diff --git a/src/env_var.rs b/src/env_var.rs
index 45b19c6389..5ec689843e 100644
--- a/src/env_var.rs
+++ b/src/env_var.rs
@@ -54,8 +54,6 @@ mod tests {
     use std::ffi::{OsStr, OsString};
 
     use super::*;
-    #[cfg(windows)]
-    use crate::cli::self_update::{RegistryGuard, USER_PATH};
     use crate::process::TestProcess;
     use crate::test::Env;
 
@@ -67,8 +65,6 @@ mod tests {
             env::join_paths(["/home/a/.cargo/bin", "/home/b/.cargo/bin"].iter()).unwrap(),
         );
         let tp = TestProcess::with_vars(vars);
-        #[cfg(windows)]
-        let _path_guard = RegistryGuard::new(&USER_PATH).unwrap();
         let mut path_entries = vec![];
         let mut cmd = Command::new("test");
 
@@ -115,8 +111,6 @@ mod tests {
             env::join_paths(["/home/a/.cargo/bin", "/home/b/.cargo/bin"].iter()).unwrap(),
         );
         let tp = TestProcess::with_vars(vars);
-        #[cfg(windows)]
-        let _path_guard = RegistryGuard::new(&USER_PATH).unwrap();
 
         #[track_caller]
         fn check(tp: &TestProcess, path_entries: Vec<PathBuf>, append: &str, expected: &[&str]) {
diff --git a/src/install.rs b/src/install.rs
index b7f4df76b9..bb5e275c8b 100644
--- a/src/install.rs
+++ b/src/install.rs
@@ -126,11 +126,12 @@ impl InstallMethod<'_, '_> {
 
     fn local_name(&self) -> LocalToolchainName {
         match self {
-            InstallMethod::Copy { dest, .. } => (*dest).into(),
-            InstallMethod::Link { dest, .. } => (*dest).into(),
+            InstallMethod::Copy { dest, .. } | InstallMethod::Link { dest, .. } => {
+                (*dest).clone().into()
+            }
             InstallMethod::Dist(DistOptions {
                 toolchain: desc, ..
-            }) => (*desc).into(),
+            }) => (*desc).clone().into(),
         }
     }
 
@@ -140,13 +141,14 @@ impl InstallMethod<'_, '_> {
 
     fn dest_path(&self) -> PathBuf {
         match self {
-            InstallMethod::Copy { cfg, dest, .. } => cfg.toolchain_path(&(*dest).into()),
-            InstallMethod::Link { cfg, dest, .. } => cfg.toolchain_path(&(*dest).into()),
+            InstallMethod::Copy { cfg, dest, .. } | InstallMethod::Link { cfg, dest, .. } => {
+                cfg.toolchain_path(&(*dest).clone().into())
+            }
             InstallMethod::Dist(DistOptions {
                 cfg,
                 toolchain: desc,
                 ..
-            }) => cfg.toolchain_path(&(*desc).into()),
+            }) => cfg.toolchain_path(&(*desc).clone().into()),
         }
     }
 }
diff --git a/src/settings.rs b/src/settings.rs
index 42dc7ceebf..cc84e5e4b9 100644
--- a/src/settings.rs
+++ b/src/settings.rs
@@ -15,7 +15,7 @@ use crate::utils;
 
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct SettingsFile {
-    path: PathBuf,
+    pub(crate) path: PathBuf,
     cache: RefCell<Option<Settings>>,
 }
 
@@ -29,7 +29,7 @@ impl SettingsFile {
 
     fn write_settings(&self) -> Result<()> {
         let settings = self.cache.borrow();
-        utils::write_file(
+        utils::write_locked_file(
             "settings",
             &self.path,
             &settings.as_ref().unwrap().stringify()?,
@@ -38,25 +38,18 @@ impl SettingsFile {
     }
 
     fn read_settings(&self) -> Result<()> {
-        let mut needs_save = false;
-        {
-            let b = self.cache.borrow();
-            if b.is_none() {
-                drop(b);
-                *self.cache.borrow_mut() = Some(if utils::is_file(&self.path) {
-                    let content = utils::read_file("settings", &self.path)?;
-                    Settings::parse(&content).with_context(|| RustupError::ParsingFile {
-                        name: "settings",
-                        path: self.path.clone(),
-                    })?
-                } else {
-                    needs_save = true;
-                    Default::default()
-                });
-            }
-        }
-        if needs_save {
-            self.write_settings()?;
+        let b = self.cache.borrow();
+        if b.is_none() {
+            drop(b);
+            *self.cache.borrow_mut() = Some(if utils::is_file(&self.path) {
+                let content = utils::read_locked_file("settings", &self.path)?;
+                Settings::parse(&content).with_context(|| RustupError::ParsingFile {
+                    name: "settings",
+                    path: self.path.clone(),
+                })?
+            } else {
+                Settings::default()
+            });
         }
         Ok(())
     }
diff --git a/src/test.rs b/src/test.rs
index 023d73aea4..3cc7901db3 100644
--- a/src/test.rs
+++ b/src/test.rs
@@ -23,8 +23,13 @@ use sha2::{Digest, Sha256};
 use crate::dist::TargetTuple;
 use crate::process::TestProcess;
 
+#[cfg(all(windows, any(test, feature = "test")))]
+pub(crate) fn test_id() -> String {
+    crate::utils::raw::random_string(8)
+}
+
 #[cfg(windows)]
-pub use crate::cli::self_update::{RegistryGuard, RegistryValueId, USER_PATH, get_path};
+pub use crate::cli::self_update::{RUSTUP_REGISTRY_TEST_ID, RegistryValueId, USER_PATH, get_path};
 
 mod clitools;
 pub use clitools::{
diff --git a/src/test/clitools.rs b/src/test/clitools.rs
index 2eb666ee92..0949da1e13 100644
--- a/src/test/clitools.rs
+++ b/src/test/clitools.rs
@@ -31,6 +31,9 @@ use crate::test::tempdir_in_with_prefix;
 use crate::test::this_host_tuple;
 use crate::utils;
 
+#[cfg(windows)]
+use crate::{cli::self_update::RUSTUP_REGISTRY_TEST_ID, test::test_id};
+
 use super::{
     CROSS_ARCH1, CROSS_ARCH2, MULTI_ARCH1,
     dist::{MockDistServer, MockManifestVersion, Release, RlsStatus, change_channel_date},
@@ -62,6 +65,9 @@ pub struct Config {
     pub workdir: RefCell<PathBuf>,
     /// This is the test root for keeping stuff together
     test_root_dir: PathBuf,
+    /// Per-test Windows registry ID.
+    #[cfg(windows)]
+    pub test_registry_id: String,
 }
 
 /// Helper type to simplify assertions of a command's output.
@@ -322,6 +328,9 @@ impl Config {
         if let Some(root) = self.rustup_update_root.as_ref() {
             cmd.env("RUSTUP_UPDATE_ROOT", root);
         }
+
+        #[cfg(windows)]
+        cmd.env(RUSTUP_REGISTRY_TEST_ID, &self.test_registry_id);
     }
 
     /// Returns an [`Assert`] object to check the output of running the command
@@ -810,6 +819,8 @@ async fn setup_test_state(test_dist_dir: TempDir) -> (TempDir, Config) {
         rustup_update_root: None,
         workdir: RefCell::new(workdir),
         test_root_dir: test_dir.path().to_path_buf(),
+        #[cfg(windows)]
+        test_registry_id: test_id(),
     };
 
     let build_path = built_exe_dir.join(format!("rustup-init{EXE_SUFFIX}"));
diff --git a/src/toolchain/distributable.rs b/src/toolchain/distributable.rs
index a76776fa07..aa06931ff6 100644
--- a/src/toolchain/distributable.rs
+++ b/src/toolchain/distributable.rs
@@ -58,7 +58,7 @@ impl<'a> DistributableToolchain<'a> {
     }
 
     pub(crate) fn new(cfg: &'a Cfg<'a>, desc: ToolchainDesc) -> Result<Self, RustupError> {
-        Toolchain::new(cfg, (&desc).into()).map(|toolchain| Self { toolchain, desc })
+        Toolchain::new(cfg, desc.clone().into()).map(|toolchain| Self { toolchain, desc })
     }
 
     pub(crate) fn desc(&self) -> &ToolchainDesc {
@@ -439,12 +439,14 @@ impl<'a> DistributableToolchain<'a> {
     }
 
     pub async fn fetch_dist_manifest(&self) -> anyhow::Result<Option<ManifestWithHash>> {
+        let prefix = InstallPrefix::from(self.toolchain.path());
+        let update_hash = if prefix.dist_manifest().is_some() {
+            Some(self.toolchain.cfg.get_hash_file(&self.desc, false)?)
+        } else {
+            None
+        };
         DownloadCfg::new(self.toolchain.cfg)
-            .dl_v2_manifest(
-                Some(&self.toolchain.cfg.get_hash_file(&self.desc, false)?),
-                &self.desc,
-                self.toolchain.cfg,
-            )
+            .dl_v2_manifest(update_hash.as_deref(), &self.desc, self.toolchain.cfg)
             .await
     }
 
diff --git a/src/toolchain/names.rs b/src/toolchain/names.rs
index 37d92b9912..f5181246b5 100644
--- a/src/toolchain/names.rs
+++ b/src/toolchain/names.rs
@@ -71,60 +71,6 @@ pub enum InvalidName {
     PlusPrefix(String),
 }
 
-macro_rules! from_variant {
-    ($from:ident, $to:ident, $variant:expr) => {
-        impl From<$from> for $to {
-            fn from(value: $from) -> Self {
-                $variant(value)
-            }
-        }
-    };
-}
-
-macro_rules! try_from_str {
-    ($to:ident) => {
-        try_from_str!(&str, $to);
-
-        impl TryFrom<String> for $to {
-            type Error = InvalidName;
-
-            fn try_from(value: String) -> std::result::Result<Self, Self::Error> {
-                $to::validate(&value)
-            }
-        }
-
-        impl FromStr for $to {
-            type Err = InvalidName;
-
-            fn from_str(value: &str) -> std::result::Result<Self, Self::Err> {
-                $to::validate(value)
-            }
-        }
-    };
-    ($from:ty, $to:ident) => {
-        impl TryFrom<$from> for $to {
-            type Error = InvalidName;
-
-            fn try_from(value: $from) -> std::result::Result<Self, Self::Error> {
-                $to::validate(value)
-            }
-        }
-    };
-}
-
-/// Common validate rules for all sorts of toolchain names
-fn validate(candidate: &str) -> Result<&str, InvalidName> {
-    if let Some(without_plus) = candidate.strip_prefix('+') {
-        return Err(InvalidName::PlusPrefix(without_plus.to_string()));
-    }
-    let normalized_name = candidate.trim_end_matches('/');
-    if normalized_name.is_empty() {
-        Err(InvalidName::ToolchainName(candidate.into()))
-    } else {
-        Ok(normalized_name)
-    }
-}
-
 /// A toolchain name from user input.
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub(crate) enum ResolvableToolchainName {
@@ -140,24 +86,26 @@ impl ResolvableToolchainName {
             Self::Official(desc) => ToolchainName::Official(desc.resolve(host)?),
         })
     }
+}
 
-    // If candidate could be resolved, return a ready to resolve version of it.
+impl FromStr for ResolvableToolchainName {
+    type Err = InvalidName;
+
+    // If value could be resolved, return a ready to resolve version of it.
     // Otherwise error.
-    fn validate(candidate: &str) -> Result<Self, InvalidName> {
-        let candidate = validate(candidate)?;
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        let candidate = normalize_name(value)?;
         if let Ok(desc) = PartialToolchainDesc::from_str(candidate) {
             return Ok(Self::Official(desc));
         }
 
-        match CustomToolchainName::try_from(candidate) {
+        match CustomToolchainName::from_str(candidate) {
             Ok(custom) => Ok(Self::Custom(custom)),
             Err(_) => Err(InvalidName::ToolchainName(candidate.into())),
         }
     }
 }
 
-try_from_str!(ResolvableToolchainName);
-
 impl From<&PartialToolchainDesc> for ResolvableToolchainName {
     fn from(value: &PartialToolchainDesc) -> Self {
         Self::Official(value.to_owned())
@@ -182,19 +130,19 @@ pub(crate) enum MaybeResolvableToolchainName {
     None,
 }
 
-impl MaybeResolvableToolchainName {
-    // If candidate could be resolved, return a ready to resolve version of it.
+impl FromStr for MaybeResolvableToolchainName {
+    type Err = InvalidName;
+
+    // If value could be resolved, return a ready to resolve version of it.
     // Otherwise error.
-    fn validate(candidate: &str) -> Result<Self, InvalidName> {
-        Ok(match validate(candidate)? {
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        Ok(match normalize_name(value)? {
             "none" => Self::None,
-            candidate => Self::Some(ResolvableToolchainName::validate(candidate)?),
+            candidate => Self::Some(ResolvableToolchainName::from_str(candidate)?),
         })
     }
 }
 
-try_from_str!(MaybeResolvableToolchainName);
-
 impl Display for MaybeResolvableToolchainName {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
@@ -212,9 +160,11 @@ pub(crate) enum MaybeOfficialToolchainName {
     Some(PartialToolchainDesc),
 }
 
-impl MaybeOfficialToolchainName {
-    fn validate(candidate: &str) -> Result<Self, InvalidName> {
-        Ok(match validate(candidate)? {
+impl FromStr for MaybeOfficialToolchainName {
+    type Err = InvalidName;
+
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        Ok(match normalize_name(value)? {
             "none" => Self::None,
             candidate => Self::Some(
                 PartialToolchainDesc::from_str(candidate)
@@ -224,8 +174,6 @@ impl MaybeOfficialToolchainName {
     }
 }
 
-try_from_str!(MaybeOfficialToolchainName);
-
 impl Display for MaybeOfficialToolchainName {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
@@ -244,26 +192,35 @@ pub enum ToolchainName {
     Custom(CustomToolchainName),
 }
 
-impl ToolchainName {
+impl From<ToolchainDesc> for ToolchainName {
+    fn from(value: ToolchainDesc) -> Self {
+        Self::Official(value)
+    }
+}
+
+impl From<CustomToolchainName> for ToolchainName {
+    fn from(value: CustomToolchainName) -> Self {
+        Self::Custom(value)
+    }
+}
+
+impl FromStr for ToolchainName {
+    type Err = InvalidName;
+
     /// If the string is already resolved, allow direct conversion
-    fn validate(candidate: &str) -> Result<Self, InvalidName> {
-        let candidate = validate(candidate)?;
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        let candidate = normalize_name(value)?;
         if let Ok(desc) = ToolchainDesc::from_str(candidate) {
             return Ok(Self::Official(desc));
         }
 
-        match CustomToolchainName::try_from(candidate) {
+        match CustomToolchainName::from_str(candidate) {
             Ok(custom) => Ok(Self::Custom(custom)),
             Err(_) => Err(InvalidName::ToolchainName(candidate.into())),
         }
     }
 }
 
-from_variant!(ToolchainDesc, ToolchainName, ToolchainName::Official);
-from_variant!(CustomToolchainName, ToolchainName, ToolchainName::Custom);
-
-try_from_str!(ToolchainName);
-
 impl Display for ToolchainName {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
@@ -290,11 +247,15 @@ impl ResolvableLocalToolchainName {
             Self::Path(t) => Ok(LocalToolchainName::Path(t)),
         }
     }
+}
+
+impl FromStr for ResolvableLocalToolchainName {
+    type Err = InvalidName;
 
-    /// Validates if the string is a resolvable toolchain, or a path based toolchain.
-    fn validate(candidate: &str) -> Result<Self, InvalidName> {
-        let candidate = validate(candidate)?;
-        if let Ok(name) = ResolvableToolchainName::try_from(candidate) {
+    /// Parses a resolvable toolchain, or a path based toolchain.
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        let candidate = normalize_name(value)?;
+        if let Ok(name) = ResolvableToolchainName::from_str(candidate) {
             return Ok(Self::Named(name));
         }
 
@@ -304,8 +265,6 @@ impl ResolvableLocalToolchainName {
     }
 }
 
-try_from_str!(ResolvableLocalToolchainName);
-
 impl Display for ResolvableLocalToolchainName {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
@@ -326,15 +285,21 @@ pub(crate) enum LocalToolchainName {
     Path(PathBasedToolchainName),
 }
 
-impl From<&ToolchainDesc> for LocalToolchainName {
-    fn from(value: &ToolchainDesc) -> Self {
-        ToolchainName::Official(value.to_owned()).into()
+impl From<ToolchainName> for LocalToolchainName {
+    fn from(value: ToolchainName) -> Self {
+        Self::Named(value)
     }
 }
 
-impl From<&CustomToolchainName> for LocalToolchainName {
-    fn from(value: &CustomToolchainName) -> Self {
-        ToolchainName::Custom(value.to_owned()).into()
+impl From<PathBasedToolchainName> for LocalToolchainName {
+    fn from(value: PathBasedToolchainName) -> Self {
+        Self::Path(value)
+    }
+}
+
+impl From<ToolchainDesc> for LocalToolchainName {
+    fn from(value: ToolchainDesc) -> Self {
+        ToolchainName::Official(value).into()
     }
 }
 
@@ -344,13 +309,6 @@ impl From<CustomToolchainName> for LocalToolchainName {
     }
 }
 
-from_variant!(ToolchainName, LocalToolchainName, LocalToolchainName::Named);
-from_variant!(
-    PathBasedToolchainName,
-    LocalToolchainName,
-    LocalToolchainName::Path
-);
-
 impl PartialEq<ToolchainName> for LocalToolchainName {
     fn eq(&self, other: &ToolchainName) -> bool {
         match self {
@@ -374,9 +332,19 @@ impl Display for LocalToolchainName {
 #[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
 pub struct CustomToolchainName(String);
 
-impl CustomToolchainName {
-    fn validate(candidate: &str) -> Result<Self, InvalidName> {
-        let candidate = validate(candidate)?;
+impl Deref for CustomToolchainName {
+    type Target = str;
+
+    fn deref(&self) -> &str {
+        &self.0
+    }
+}
+
+impl FromStr for CustomToolchainName {
+    type Err = InvalidName;
+
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        let candidate = normalize_name(value)?;
         if candidate.parse::<PartialToolchainDesc>().is_ok()
             || candidate == "none"
             || candidate.contains('/')
@@ -389,16 +357,6 @@ impl CustomToolchainName {
     }
 }
 
-impl Deref for CustomToolchainName {
-    type Target = str;
-
-    fn deref(&self) -> &str {
-        &self.0
-    }
-}
-
-try_from_str!(CustomToolchainName);
-
 impl Display for CustomToolchainName {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "{}", self.0)
@@ -460,6 +418,23 @@ impl Deref for PathBasedToolchainName {
     }
 }
 
+/// Normalization shared by all sorts of toolchain names.
+///
+/// Strips the trailing slashes a shell may have completed onto a toolchain
+/// directory, and rejects the `+toolchain` argument form along with names that
+/// are empty once normalized.
+fn normalize_name(candidate: &str) -> Result<&str, InvalidName> {
+    if let Some(without_plus) = candidate.strip_prefix('+') {
+        return Err(InvalidName::PlusPrefix(without_plus.to_string()));
+    }
+    let normalized_name = candidate.trim_end_matches('/');
+    if normalized_name.is_empty() {
+        Err(InvalidName::ToolchainName(candidate.into()))
+    } else {
+        Ok(normalized_name)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::str::FromStr;
@@ -528,12 +503,12 @@ mod tests {
 
         #[test]
         fn test_parse_custom(name in arb_custom_name()) {
-            CustomToolchainName::try_from(name).unwrap();
+            CustomToolchainName::from_str(&name).unwrap();
         }
 
         #[test]
         fn test_parse_resolvable_name(name in arb_resolvable_name()) {
-            ResolvableToolchainName::try_from(name).unwrap();
+            ResolvableToolchainName::from_str(&name).unwrap();
         }
 
         // TODO: This needs some thought
@@ -570,7 +545,7 @@ mod tests {
             "this.is.not-a+semver",
         ]
         .into_iter()
-        .map(|s| ToolchainName::try_from(s).unwrap())
+        .map(|s| ToolchainName::from_str(s).unwrap())
         .collect::<Vec<_>>();
 
         let mut v = vec![
@@ -595,7 +570,7 @@ mod tests {
             "the cake is a lie",
         ]
         .into_iter()
-        .map(|s| ToolchainName::try_from(s).unwrap())
+        .map(|s| ToolchainName::from_str(s).unwrap())
         .collect::<Vec<_>>();
 
         v.sort();
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
index fdb079ccaf..414a5687a4 100644
--- a/src/utils/mod.rs
+++ b/src/utils/mod.rs
@@ -87,6 +87,13 @@ pub fn read_file(name: &'static str, path: &Path) -> Result<String> {
     })
 }
 
+pub(crate) fn read_locked_file(name: &'static str, path: &Path) -> Result<String> {
+    raw::read_locked_file(path).with_context(|| RustupError::ReadingFile {
+        name,
+        path: PathBuf::from(path),
+    })
+}
+
 pub fn write_file(name: &'static str, path: &Path, contents: &str) -> Result<()> {
     raw::write_file(path, contents).with_context(|| RustupError::WritingFile {
         name,
@@ -94,6 +101,13 @@ pub fn write_file(name: &'static str, path: &Path, contents: &str) -> Result<()>
     })
 }
 
+pub(crate) fn write_locked_file(name: &'static str, path: &Path, contents: &str) -> Result<()> {
+    raw::write_locked_file(path, contents).with_context(|| RustupError::WritingFile {
+        name,
+        path: PathBuf::from(path),
+    })
+}
+
 pub(crate) fn append_file(name: &'static str, path: &Path, line: &str) -> Result<()> {
     raw::append_file(path, line).with_context(|| RustupError::WritingFile {
         name,
diff --git a/src/utils/raw.rs b/src/utils/raw.rs
index ba439ae731..70f27f3d42 100644
--- a/src/utils/raw.rs
+++ b/src/utils/raw.rs
@@ -3,7 +3,7 @@ use std::env;
 use std::fs;
 use std::fs::File;
 use std::io;
-use std::io::Write;
+use std::io::{Read, Seek, SeekFrom, Write};
 use std::path::Path;
 use std::str;
 
@@ -60,6 +60,21 @@ pub fn path_exists<P: AsRef<Path>>(path: P) -> bool {
     fs::metadata(path).is_ok()
 }
 
+pub(crate) fn read_locked_file(path: &Path) -> io::Result<String> {
+    let mut file = File::open(path)?;
+    file.lock_shared()?;
+
+    let size = file
+        .metadata()
+        .map(|metadata| usize::try_from(metadata.len()).unwrap_or(usize::MAX))
+        .ok();
+    let mut contents = String::new();
+    contents.try_reserve_exact(size.unwrap_or(0))?;
+    file.read_to_string(&mut contents)?;
+
+    Ok(contents)
+}
+
 pub(crate) fn random_string(length: usize) -> String {
     const CHARSET: &[u8] = b"abcdefghijklmnopqrstuvwxyz0123456789_";
     let mut rng = rand::rng();
@@ -82,6 +97,24 @@ pub fn write_file(path: &Path, contents: &str) -> io::Result<()> {
     Ok(())
 }
 
+pub(crate) fn write_locked_file(path: &Path, contents: &str) -> io::Result<()> {
+    let mut file = fs::OpenOptions::new()
+        .read(true)
+        .write(true)
+        .create(true)
+        // Truncation must happen after the exclusive lock is held.
+        .truncate(false)
+        .open(path)?;
+
+    file.lock()?;
+    file.set_len(0)?;
+    file.seek(SeekFrom::Start(0))?;
+    Write::write_all(&mut file, contents.as_bytes())?;
+    file.sync_data()?;
+
+    Ok(())
+}
+
 pub(crate) fn filter_file<F: FnMut(&str) -> bool>(
     src: &Path,
     dest: &Path,
@@ -350,3 +383,20 @@ pub(crate) mod windows {
         inner(s.as_ref())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn locked_file_round_trip_truncates_previous_contents() -> io::Result<()> {
+        let temp_dir = tempfile::tempdir()?;
+        let path = temp_dir.path().join("state.toml");
+
+        write_locked_file(&path, "last_release_notified_secs = 123456\n")?;
+        write_locked_file(&path, "version = \"12\"\n")?;
+
+        assert_eq!(read_locked_file(&path)?, "version = \"12\"\n");
+        Ok(())
+    }
+}
diff --git a/tests/suite/cli_inst_interactive.rs b/tests/suite/cli_inst_interactive.rs
index 9b75e951c4..95c761f4bc 100644
--- a/tests/suite/cli_inst_interactive.rs
+++ b/tests/suite/cli_inst_interactive.rs
@@ -1,12 +1,11 @@
 //! Tests of the interactive console installer
 
 use std::env::consts::EXE_SUFFIX;
+use std::fs;
 use std::io::Write;
 use std::process::Stdio;
 
 use rustup::test::{Assert, CliTestContext, Config, SanitizedOutput, Scenario, this_host_tuple};
-#[cfg(windows)]
-use rustup::test::{RegistryGuard, USER_PATH};
 use rustup::utils::raw;
 
 fn run_input(config: &Config, args: &[&str], input: &str) -> Assert {
@@ -44,8 +43,6 @@ fn run_input_with_env(config: &Config, args: &[&str], input: &str, env: &[(&str,
 #[tokio::test]
 async fn update() {
     let cx = CliTestContext::new(Scenario::SimpleV2).await;
-    #[cfg(windows)]
-    let _path_guard = RegistryGuard::new(&USER_PATH).unwrap();
 
     run_input(&cx.config, &["rustup-init"], "\n\n");
     run_input(&cx.config, &["rustup-init"], "\n\n").is_ok();
@@ -100,8 +97,6 @@ Rust is installed now. Great!
 #[tokio::test]
 async fn smoke_case_install_with_path_install() {
     let cx = CliTestContext::new(Scenario::SimpleV2).await;
-    #[cfg(windows)]
-    let _path_guard = RegistryGuard::new(&USER_PATH).unwrap();
 
     run_input(&cx.config, &["rustup-init"], "\n\n")
         .is_ok()
@@ -497,7 +492,8 @@ async fn test_warn_if_complete_profile_is_used() {
         .await
         .with_stderr(snapbox::str![[r#"
 ...
-warn: downloading with complete profile isn't recommended unless you are a developer of the rust language
+warn: downloading with the `complete` profile is deprecated
+help: consider switching to the `default` profile with `rustup set profile default`
 ...
 "#]])
         .is_ok();
@@ -685,3 +681,40 @@ warn: many Rust crates require a system C toolchain to build
 ...
 "#]]);
 }
+
+#[tokio::test]
+async fn install_rejection_leaves_rustupdir_untouched() {
+    let cx = CliTestContext::new(Scenario::SimpleV2).await;
+
+    let rustupdir = &cx.config.rustupdir.rustupdir;
+    let settings_file = &rustupdir.join("settings.toml");
+    fs::remove_dir_all(rustupdir).unwrap();
+
+    run_input(&cx.config, &["rustup-init", "--no-modify-path"], "3\n")
+        .with_stdout(snapbox::str![[r#"
+...
+This path needs to be in your PATH environment variable,
+but will not be added automatically.
+
+You can uninstall at any time with rustup self uninstall and
+these changes will be reverted.
+
+Current installation options:
+
+
+    default host tuple: [HOST_TUPLE]
+     default toolchain: stable (default)
+               profile: default
+  modify PATH variable: no
+
+1) Proceed with standard installation (default - just press enter)
+2) Customize installation
+3) Cancel installation
+>
+
+"#]])
+        .is_ok();
+
+    assert!(!settings_file.exists());
+    assert!(!rustupdir.exists());
+}
diff --git a/tests/suite/cli_paths.rs b/tests/suite/cli_paths.rs
index f102dd5234..654e25413a 100644
--- a/tests/suite/cli_paths.rs
+++ b/tests/suite/cli_paths.rs
@@ -348,6 +348,41 @@ error: could not amend shell profile[..]
         }
     }
 
+    #[tokio::test]
+    async fn install_preserves_guarded_legacy_source() {
+        let cx = CliTestContext::new(Scenario::Empty).await;
+        let profile = cx.config.homedir.join(".bash_profile");
+        let guarded_source = "[ -f \"$HOME/.cargo/env\" ] && source \"$HOME/.cargo/env\"\n";
+        raw::write_file(&profile, guarded_source).unwrap();
+
+        let mut cmd = cx.config.cmd("rustup-init", &INIT_NONE[1..]);
+        cmd.env_remove("CARGO_HOME");
+        assert!(cmd.output().unwrap().status.success());
+
+        let new_profile = fs::read_to_string(&profile).unwrap();
+        let expected = guarded_source.to_owned() + &source("$HOME/.cargo", POSIX_SH);
+        assert_eq!(new_profile, expected);
+    }
+
+    #[tokio::test]
+    async fn uninstall_preserves_guarded_source() {
+        let cx = CliTestContext::new(Scenario::Empty).await;
+        let profile = cx.config.homedir.join(".bash_profile");
+        let guarded_source = "[ -f \"$HOME/.cargo/env\" ] && . \"$HOME/.cargo/env\"\n";
+        raw::write_file(&profile, guarded_source).unwrap();
+
+        let mut cmd = cx.config.cmd("rustup-init", &INIT_NONE[1..]);
+        cmd.env_remove("CARGO_HOME");
+        assert!(cmd.output().unwrap().status.success());
+
+        let mut cmd = cx.config.cmd("rustup", ["self", "uninstall", "-y"]);
+        cmd.env_remove("CARGO_HOME");
+        assert!(cmd.output().unwrap().status.success());
+
+        let new_profile = fs::read_to_string(&profile).unwrap();
+        assert_eq!(new_profile, guarded_source);
+    }
+
     #[tokio::test]
     async fn uninstall_cleans_up_legacy_paths() {
         let cx = CliTestContext::new(Scenario::Empty).await;
@@ -434,46 +469,54 @@ error: could not amend shell profile[..]
 
 #[cfg(windows)]
 mod windows {
+    use retry::delay::{Fibonacci, jitter};
+    use retry::{OperationResult, retry};
+
     use super::INIT_NONE;
     use rustup::test::{CliTestContext, Scenario};
-    use rustup::test::{RegistryGuard, USER_PATH, get_path};
+    use rustup::test::{USER_PATH, get_path};
 
-    use windows_registry::{HSTRING, Value};
+    use windows_registry::{CURRENT_USER, HSTRING, Value};
 
     #[tokio::test]
     /// Smoke test for end-to-end code connectivity of the installer path mgmt on windows.
     async fn install_uninstall_affect_path() {
         let cx = CliTestContext::new(Scenario::Empty).await;
-        let _guard = RegistryGuard::new(&USER_PATH).unwrap();
+        let test_id = &cx.config.test_registry_id;
         let cfg_path = cx.config.cargodir.join("bin").display().to_string();
-        let get_path_ = || {
-            HSTRING::try_from(get_path().unwrap().unwrap())
-                .unwrap()
-                .to_string()
+        let read_path = |test_id: &str| -> Option<String> {
+            retry(
+                Fibonacci::from_millis(1).map(jitter).take(21),
+                || match get_path(test_id).unwrap() {
+                    Some(v) => OperationResult::Ok(HSTRING::try_from(v).unwrap().to_string()),
+                    None => OperationResult::Retry(()),
+                },
+            )
+            .ok()
         };
 
         cx.config.expect(&INIT_NONE).await.is_ok();
+        let after_install = read_path(test_id).unwrap_or_default();
         assert!(
-            get_path_().contains(cfg_path.trim_matches('"')),
-            "`{}` not in `{}`",
-            cfg_path,
-            get_path_()
+            after_install.contains(cfg_path.trim_matches('"')),
+            "`{cfg_path}` not in `{after_install}`",
         );
 
         cx.config
             .expect(&["rustup", "self", "uninstall", "-y"])
             .await
             .is_ok();
-        assert!(!get_path_().contains(&cfg_path));
+        let after_uninstall = read_path(test_id).unwrap_or_default();
+        assert!(!after_uninstall.contains(&cfg_path));
     }
 
     #[tokio::test]
     async fn uninstall_doesnt_affect_path_with_no_modify_path() {
         let cx = CliTestContext::new(Scenario::Empty).await;
-        let _guard = RegistryGuard::new(&USER_PATH).unwrap();
+        let test_id = &cx.config.test_registry_id;
         let cfg_path = cx.config.cargodir.join("bin").display().to_string();
         let get_path_ = || {
-            HSTRING::try_from(get_path().unwrap().unwrap())
+            HSTRING::try_from(get_path(test_id).unwrap().unwrap())
                 .unwrap()
                 .to_string()
         };
@@ -496,10 +539,10 @@ mod windows {
     async fn install_uninstall_affect_path_with_non_unicode() {
         use std::os::windows::ffi::OsStrExt;
 
-        use windows_registry::{CURRENT_USER, Type};
+        use windows_registry::Type;
 
         let cx = CliTestContext::new(Scenario::Empty).await;
-        let _guard = RegistryGuard::new(&USER_PATH).unwrap();
+        let test_id = &cx.config.test_registry_id;
         // Set up a non unicode PATH
         let mut reg_value = Value::from([
             0x00, 0xD8, // leading surrogate
@@ -507,10 +550,8 @@ mod windows {
             0x00, 0x00, // null
         ]);
         reg_value.set_ty(Type::ExpandString);
-        CURRENT_USER
-            .create("Environment")
-            .unwrap()
-            .set_value("PATH", &reg_value)
+        USER_PATH
+            .set(Some(&reg_value), test_id, CURRENT_USER)
             .unwrap();
 
         // compute expected path after installation
@@ -529,12 +570,12 @@ mod windows {
         expected.set_ty(Type::ExpandString);
 
         cx.config.expect(&INIT_NONE).await.is_ok();
-        assert_eq!(get_path().unwrap().unwrap(), expected);
+        assert_eq!(get_path(test_id).unwrap().unwrap(), expected);
 
         cx.config
             .expect(&["rustup", "self", "uninstall", "-y"])
             .await
             .is_ok();
-        assert_eq!(get_path().unwrap().unwrap(), reg_value);
+        assert_eq!(get_path(test_id).unwrap().unwrap(), reg_value);
     }
 }
diff --git a/tests/suite/cli_rustup.rs b/tests/suite/cli_rustup.rs
index 91c3891907..76ca060212 100644
--- a/tests/suite/cli_rustup.rs
+++ b/tests/suite/cli_rustup.rs
@@ -353,7 +353,7 @@ async fn add_target() {
     let cx = CliTestContext::new(Scenario::SimpleV2).await;
     let path = format!(
         "toolchains/nightly-{}/lib/rustlib/{}/lib/libstd.rlib",
-        &this_host_tuple(),
+        this_host_tuple(),
         CROSS_ARCH1
     );
     cx.config
@@ -372,7 +372,7 @@ async fn remove_target() {
     let cx = CliTestContext::new(Scenario::SimpleV2).await;
     let path = format!(
         "toolchains/nightly-{}/lib/rustlib/{}/lib/libstd.rlib",
-        &this_host_tuple(),
+        this_host_tuple(),
         CROSS_ARCH1
     );
     cx.config
@@ -404,13 +404,13 @@ async fn add_remove_multiple_targets() {
         .is_ok();
     let path = format!(
         "toolchains/nightly-{}/lib/rustlib/{}/lib/libstd.rlib",
-        &this_host_tuple(),
+        this_host_tuple(),
         CROSS_ARCH1
     );
     assert!(cx.config.rustupdir.has(path));
     let path = format!(
         "toolchains/nightly-{}/lib/rustlib/{}/lib/libstd.rlib",
-        &this_host_tuple(),
+        this_host_tuple(),
         CROSS_ARCH2
     );
     assert!(cx.config.rustupdir.has(path));
@@ -421,13 +421,13 @@ async fn add_remove_multiple_targets() {
         .is_ok();
     let path = format!(
         "toolchains/nightly-{}/lib/rustlib/{}/lib/libstd.rlib",
-        &this_host_tuple(),
+        this_host_tuple(),
         CROSS_ARCH1
     );
     assert!(!cx.config.rustupdir.has(path));
     let path = format!(
         "toolchains/nightly-{}/lib/rustlib/{}/lib/libstd.rlib",
-        &this_host_tuple(),
+        this_host_tuple(),
         CROSS_ARCH2
     );
     assert!(!cx.config.rustupdir.has(path));
@@ -474,7 +474,7 @@ async fn add_target_explicit() {
     let cx = CliTestContext::new(Scenario::SimpleV2).await;
     let path = format!(
         "toolchains/nightly-{}/lib/rustlib/{}/lib/libstd.rlib",
-        &this_host_tuple(),
+        this_host_tuple(),
         CROSS_ARCH1
     );
     cx.config
@@ -500,7 +500,7 @@ async fn remove_target_explicit() {
     let cx = CliTestContext::new(Scenario::SimpleV2).await;
     let path = format!(
         "toolchains/nightly-{}/lib/rustlib/{}/lib/libstd.rlib",
-        &this_host_tuple(),
+        this_host_tuple(),
         CROSS_ARCH1
     );
     cx.config
@@ -4173,14 +4173,7 @@ async fn missing_manifest_shows_reinstall_help() {
         .await
         .is_ok();
 
-    let manifest_path = cx
-        .config
-        .rustupdir
-        .join("toolchains")
-        .join(format!("nightly-{}", this_host_tuple()))
-        .join("lib")
-        .join("rustlib")
-        .join("multirust-channel-manifest.toml");
+    let manifest_path = nightly_manifest_path(&cx);
 
     fs::remove_file(&manifest_path).unwrap();
 
@@ -4195,3 +4188,51 @@ help: try reinstalling or updating the toolchain
 "#]])
         .is_err();
 }
+
+#[tokio::test]
+async fn reinstall_restores_missing_manifest() {
+    let cx = CliTestContext::new(Scenario::SimpleV2).await;
+
+    cx.config
+        .expect(["rustup", "toolchain", "install", "nightly"])
+        .await
+        .is_ok();
+
+    let manifest_path = nightly_manifest_path(&cx);
+
+    fs::remove_file(&manifest_path).unwrap();
+
+    cx.config
+        .expect(["rustup", "toolchain", "install", "nightly"])
+        .await
+        .is_ok();
+
+    assert!(manifest_path.exists());
+}
+
+#[tokio::test]
+async fn update_all_restores_missing_manifest() {
+    let cx = CliTestContext::new(Scenario::SimpleV2).await;
+
+    cx.config
+        .expect(["rustup", "toolchain", "install", "nightly"])
+        .await
+        .is_ok();
+
+    let manifest_path = nightly_manifest_path(&cx);
+    fs::remove_file(&manifest_path).unwrap();
+
+    cx.config.expect(["rustup", "update"]).await.is_ok();
+
+    assert!(manifest_path.exists());
+}
+
+fn nightly_manifest_path(cx: &CliTestContext) -> PathBuf {
+    cx.config
+        .rustupdir
+        .join("toolchains")
+        .join(format!("nightly-{}", this_host_tuple()))
+        .join("lib")
+        .join("rustlib")
+        .join("multirust-channel-manifest.toml")
+}
diff --git a/tests/suite/cli_rustup_ui/rustup_doc_cmd_help_flag.stdout.term.svg b/tests/suite/cli_rustup_ui/rustup_doc_cmd_help_flag.stdout.term.svg
index 1a2571939b..479447b6cb 100644
--- a/tests/suite/cli_rustup_ui/rustup_doc_cmd_help_flag.stdout.term.svg
+++ b/tests/suite/cli_rustup_ui/rustup_doc_cmd_help_flag.stdout.term.svg
@@ -1,4 +1,4 @@
-<svg width="835px" height="830px" xmlns="http://www.w3.org/2000/svg">
+<svg width="844px" height="938px" xmlns="http://www.w3.org/2000/svg">
   <style>
     .fg { fill: #AAAAAA }
     .bg { fill: #000000 }
@@ -42,73 +42,85 @@
 </tspan>
     <tspan x="10px" y="208px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--path</tspan><tspan>                   Only print the path to the documentation</tspan>
 </tspan>
-    <tspan x="10px" y="226px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--toolchain</tspan><tspan class="fg-cyan"> </tspan><tspan class="fg-cyan">&lt;TOOLCHAIN&gt;</tspan><tspan>  Toolchain name, such as 'stable', 'nightly', or '1.8.0'. For more</tspan>
+    <tspan x="10px" y="226px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--serve</tspan><tspan>                  Serve the documentation over a local HTTP server instead of opening</tspan>
 </tspan>
-    <tspan x="10px" y="244px"><tspan>                               information see `rustup help toolchain`</tspan>
+    <tspan x="10px" y="244px"><tspan>                               it directly as a `file://` URL</tspan>
 </tspan>
-    <tspan x="10px" y="262px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--alloc</tspan><tspan>                  The Rust core allocation and collections library</tspan>
+    <tspan x="10px" y="262px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--toolchain</tspan><tspan class="fg-cyan"> </tspan><tspan class="fg-cyan">&lt;TOOLCHAIN&gt;</tspan><tspan>  Toolchain name, such as 'stable', 'nightly', or '1.8.0'. For more</tspan>
 </tspan>
-    <tspan x="10px" y="280px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--book</tspan><tspan>                   The Rust Programming Language book</tspan>
+    <tspan x="10px" y="280px"><tspan>                               information see `rustup help toolchain`</tspan>
 </tspan>
-    <tspan x="10px" y="298px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--cargo</tspan><tspan>                  The Cargo Book</tspan>
+    <tspan x="10px" y="298px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--alloc</tspan><tspan>                  The Rust core allocation and collections library</tspan>
 </tspan>
-    <tspan x="10px" y="316px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--clippy</tspan><tspan>                 The Clippy Documentation</tspan>
+    <tspan x="10px" y="316px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--book</tspan><tspan>                   The Rust Programming Language book</tspan>
 </tspan>
-    <tspan x="10px" y="334px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--core</tspan><tspan>                   The Rust Core Library</tspan>
+    <tspan x="10px" y="334px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--cargo</tspan><tspan>                  The Cargo Book</tspan>
 </tspan>
-    <tspan x="10px" y="352px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--edition-guide</tspan><tspan>          The Rust Edition Guide</tspan>
+    <tspan x="10px" y="352px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--clippy</tspan><tspan>                 The Clippy Documentation</tspan>
 </tspan>
-    <tspan x="10px" y="370px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--embedded-book</tspan><tspan>          The Embedded Rust Book</tspan>
+    <tspan x="10px" y="370px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--core</tspan><tspan>                   The Rust Core Library</tspan>
 </tspan>
-    <tspan x="10px" y="388px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--error-codes</tspan><tspan>            The Rust Error Codes Index</tspan>
+    <tspan x="10px" y="388px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--edition-guide</tspan><tspan>          The Rust Edition Guide</tspan>
 </tspan>
-    <tspan x="10px" y="406px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--nomicon</tspan><tspan>                The Dark Arts of Advanced and Unsafe Rust Programming</tspan>
+    <tspan x="10px" y="406px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--embedded-book</tspan><tspan>          The Embedded Rust Book</tspan>
 </tspan>
-    <tspan x="10px" y="424px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--proc_macro</tspan><tspan>             A support library for macro authors when defining new macros</tspan>
+    <tspan x="10px" y="424px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--error-codes</tspan><tspan>            The Rust Error Codes Index</tspan>
 </tspan>
-    <tspan x="10px" y="442px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--reference</tspan><tspan>              The Rust Reference</tspan>
+    <tspan x="10px" y="442px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--nomicon</tspan><tspan>                The Dark Arts of Advanced and Unsafe Rust Programming</tspan>
 </tspan>
-    <tspan x="10px" y="460px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--releases</tspan><tspan>               Rust Release Notes</tspan>
+    <tspan x="10px" y="460px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--proc_macro</tspan><tspan>             A support library for macro authors when defining new macros</tspan>
 </tspan>
-    <tspan x="10px" y="478px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--rust-by-example</tspan><tspan>        A collection of runnable examples that illustrate various Rust</tspan>
+    <tspan x="10px" y="478px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--reference</tspan><tspan>              The Rust Reference</tspan>
 </tspan>
-    <tspan x="10px" y="496px"><tspan>                               concepts and standard libraries</tspan>
+    <tspan x="10px" y="496px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--releases</tspan><tspan>               Rust Release Notes</tspan>
 </tspan>
-    <tspan x="10px" y="514px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--rustc</tspan><tspan>                  The compiler for the Rust programming language</tspan>
+    <tspan x="10px" y="514px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--rust-by-example</tspan><tspan>        A collection of runnable examples that illustrate various Rust</tspan>
 </tspan>
-    <tspan x="10px" y="532px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--rustc-docs</tspan><tspan>             The API documentation for the Rust compiler and other toolchain</tspan>
+    <tspan x="10px" y="532px"><tspan>                               concepts and standard libraries</tspan>
 </tspan>
-    <tspan x="10px" y="550px"><tspan>                               components</tspan>
+    <tspan x="10px" y="550px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--rustc</tspan><tspan>                  The compiler for the Rust programming language</tspan>
 </tspan>
-    <tspan x="10px" y="568px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--rustdoc</tspan><tspan>                Documentation generator for Rust projects</tspan>
+    <tspan x="10px" y="568px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--rustc-docs</tspan><tspan>             The API documentation for the Rust compiler and other toolchain</tspan>
 </tspan>
-    <tspan x="10px" y="586px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--std</tspan><tspan>                    Standard library API documentation</tspan>
+    <tspan x="10px" y="586px"><tspan>                               components</tspan>
 </tspan>
-    <tspan x="10px" y="604px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--style-guide</tspan><tspan>            The Rust Style Guide</tspan>
+    <tspan x="10px" y="604px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--rustdoc</tspan><tspan>                Documentation generator for Rust projects</tspan>
 </tspan>
-    <tspan x="10px" y="622px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--test</tspan><tspan>                   Support code for rustc's built in unit-test and micro-benchmarking</tspan>
+    <tspan x="10px" y="622px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--std</tspan><tspan>                    Standard library API documentation</tspan>
 </tspan>
-    <tspan x="10px" y="640px"><tspan>                               framework</tspan>
+    <tspan x="10px" y="640px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--style-guide</tspan><tspan>            The Rust Style Guide</tspan>
 </tspan>
-    <tspan x="10px" y="658px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--unstable-book</tspan><tspan>          The Unstable Book</tspan>
+    <tspan x="10px" y="658px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--test</tspan><tspan>                   Support code for rustc's built in unit-test and micro-benchmarking</tspan>
 </tspan>
-    <tspan x="10px" y="676px"><tspan>  </tspan><tspan class="fg-bright-cyan bold">-h</tspan><tspan>, </tspan><tspan class="fg-bright-cyan bold">--help</tspan><tspan>                   Print help</tspan>
+    <tspan x="10px" y="676px"><tspan>                               framework</tspan>
 </tspan>
-    <tspan x="10px" y="694px">
+    <tspan x="10px" y="694px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--unstable-book</tspan><tspan>          The Unstable Book</tspan>
 </tspan>
-    <tspan x="10px" y="712px"><tspan class="fg-bright-green bold">Discussion:</tspan>
+    <tspan x="10px" y="712px"><tspan>  </tspan><tspan class="fg-bright-cyan bold">-h</tspan><tspan>, </tspan><tspan class="fg-bright-cyan bold">--help</tspan><tspan>                   Print help</tspan>
 </tspan>
-    <tspan x="10px" y="730px"><tspan>  Opens the documentation for the currently active toolchain with</tspan>
+    <tspan x="10px" y="730px">
 </tspan>
-    <tspan x="10px" y="748px"><tspan>  the default browser.</tspan>
+    <tspan x="10px" y="748px"><tspan class="fg-bright-green bold">Discussion:</tspan>
 </tspan>
-    <tspan x="10px" y="766px">
+    <tspan x="10px" y="766px"><tspan>  Opens the documentation for the currently active toolchain with</tspan>
 </tspan>
-    <tspan x="10px" y="784px"><tspan>  By default, it opens the documentation index. Use the various</tspan>
+    <tspan x="10px" y="784px"><tspan>  the default browser.</tspan>
 </tspan>
-    <tspan x="10px" y="802px"><tspan>  flags to open specific pieces of documentation.</tspan>
+    <tspan x="10px" y="802px">
 </tspan>
-    <tspan x="10px" y="820px">
+    <tspan x="10px" y="820px"><tspan>  By default, it opens the documentation index. Use the various</tspan>
+</tspan>
+    <tspan x="10px" y="838px"><tspan>  flags to open specific pieces of documentation.</tspan>
+</tspan>
+    <tspan x="10px" y="856px">
+</tspan>
+    <tspan x="10px" y="874px"><tspan>  If your browser is sandboxed (e.g. installed via Snap or Flatpak) it</tspan>
+</tspan>
+    <tspan x="10px" y="892px"><tspan>  may be unable to open `file://` URLs under `~/.rustup`. Pass `--serve`</tspan>
+</tspan>
+    <tspan x="10px" y="910px"><tspan>  to serve the documentation over a local HTTP server instead.</tspan>
+</tspan>
+    <tspan x="10px" y="928px">
 </tspan>
   </text>
 
diff --git a/tests/suite/cli_rustup_ui/rustup_run_cmd_help_flag.stdout.term.svg b/tests/suite/cli_rustup_ui/rustup_run_cmd_help_flag.stdout.term.svg
index ab54a0335f..7fd96e0463 100644
--- a/tests/suite/cli_rustup_ui/rustup_run_cmd_help_flag.stdout.term.svg
+++ b/tests/suite/cli_rustup_ui/rustup_run_cmd_help_flag.stdout.term.svg
@@ -72,7 +72,7 @@
 </tspan>
     <tspan x="10px" y="478px">
 </tspan>
-    <tspan x="10px" y="496px"><tspan>    </tspan><tspan class="fg-bright-cyan bold">$ rustup run nightly cargo build</tspan>
+    <tspan x="10px" y="496px"><tspan>    </tspan><tspan class="fg-bright-cyan bold">$ rustup run --install nightly cargo build</tspan>
 </tspan>
     <tspan x="10px" y="514px">
 </tspan>
diff --git a/tests/suite/cli_rustup_ui/rustup_toolchain_cmd_install_cmd_help_flag.stdout.term.svg b/tests/suite/cli_rustup_ui/rustup_toolchain_cmd_install_cmd_help_flag.stdout.term.svg
index f996dc9902..d42f1d8930 100644
--- a/tests/suite/cli_rustup_ui/rustup_toolchain_cmd_install_cmd_help_flag.stdout.term.svg
+++ b/tests/suite/cli_rustup_ui/rustup_toolchain_cmd_install_cmd_help_flag.stdout.term.svg
@@ -1,4 +1,4 @@
-<svg width="860px" height="614px" xmlns="http://www.w3.org/2000/svg">
+<svg width="860px" height="632px" xmlns="http://www.w3.org/2000/svg">
   <style>
     .fg { fill: #AAAAAA }
     .bg { fill: #000000 }
@@ -62,29 +62,31 @@
 </tspan>
     <tspan x="10px" y="388px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--override</tspan><tspan>               Set the installed toolchain as the override for the current directory</tspan>
 </tspan>
-    <tspan x="10px" y="406px"><tspan>  </tspan><tspan class="fg-bright-cyan bold">-h</tspan><tspan>, </tspan><tspan class="fg-bright-cyan bold">--help</tspan><tspan>                   Print help</tspan>
+    <tspan x="10px" y="406px"><tspan>      </tspan><tspan class="fg-bright-cyan bold">--default</tspan><tspan>                Set the installed toolchain as the default toolchain</tspan>
 </tspan>
-    <tspan x="10px" y="424px">
+    <tspan x="10px" y="424px"><tspan>  </tspan><tspan class="fg-bright-cyan bold">-h</tspan><tspan>, </tspan><tspan class="fg-bright-cyan bold">--help</tspan><tspan>                   Print help</tspan>
 </tspan>
-    <tspan x="10px" y="442px"><tspan class="fg-bright-green bold">Discussion:</tspan>
+    <tspan x="10px" y="442px">
 </tspan>
-    <tspan x="10px" y="460px"><tspan>  Some environment variables allow you to customize certain parameters</tspan>
+    <tspan x="10px" y="460px"><tspan class="fg-bright-green bold">Discussion:</tspan>
 </tspan>
-    <tspan x="10px" y="478px"><tspan>  in toolchain installation, including:</tspan>
+    <tspan x="10px" y="478px"><tspan>  Some environment variables allow you to customize certain parameters</tspan>
 </tspan>
-    <tspan x="10px" y="496px">
+    <tspan x="10px" y="496px"><tspan>  in toolchain installation, including:</tspan>
 </tspan>
-    <tspan x="10px" y="514px"><tspan>  - `RUSTUP_CONCURRENT_DOWNLOADS`: the number of concurrent downloads.</tspan>
+    <tspan x="10px" y="514px">
 </tspan>
-    <tspan x="10px" y="532px"><tspan>  - `RUSTUP_DOWNLOAD_TIMEOUT`: the download timeout in seconds.</tspan>
+    <tspan x="10px" y="532px"><tspan>  - `RUSTUP_CONCURRENT_DOWNLOADS`: the number of concurrent downloads.</tspan>
 </tspan>
-    <tspan x="10px" y="550px">
+    <tspan x="10px" y="550px"><tspan>  - `RUSTUP_DOWNLOAD_TIMEOUT`: the download timeout in seconds.</tspan>
 </tspan>
-    <tspan x="10px" y="568px"><tspan>  See &lt;https://rust-lang.github.io/rustup/devel/environment-variables.html&gt;</tspan>
+    <tspan x="10px" y="568px">
 </tspan>
-    <tspan x="10px" y="586px"><tspan>  for more info.</tspan>
+    <tspan x="10px" y="586px"><tspan>  See &lt;https://rust-lang.github.io/rustup/devel/environment-variables.html&gt;</tspan>
 </tspan>
-    <tspan x="10px" y="604px">
+    <tspan x="10px" y="604px"><tspan>  for more info.</tspan>
+</tspan>
+    <tspan x="10px" y="622px">
 </tspan>
   </text>
 
diff --git a/tests/suite/cli_self_upd.rs b/tests/suite/cli_self_upd.rs
index 72ca1d47e5..8d5e40ae61 100644
--- a/tests/suite/cli_self_upd.rs
+++ b/tests/suite/cli_self_upd.rs
@@ -12,16 +12,16 @@ use retry::{
     delay::{Fibonacci, jitter},
     retry,
 };
+#[cfg(windows)]
+use rustup::test::RegistryValueId;
 use rustup::test::{
     CROSS_ARCH1, CliTestContext, Scenario, SelfUpdateTestContext, calc_hash, output_release_file,
     this_host_tuple,
 };
-#[cfg(windows)]
-use rustup::test::{RegistryGuard, RegistryValueId, USER_PATH};
 use rustup::utils::{self, raw};
 use rustup::{DUP_TOOLS, TOOLS};
 #[cfg(windows)]
-use windows_registry::Value;
+use windows_registry::{CURRENT_USER, Value};
 
 const TEST_VERSION: &str = "1.1.1";
 
@@ -57,8 +57,6 @@ async fn setup_installed() -> CliTestContext {
 #[tokio::test]
 async fn install_bins_to_cargo_home() {
     let cx = CliTestContext::new(Scenario::SimpleV2).await;
-    #[cfg(windows)]
-    let _path_guard = RegistryGuard::new(&USER_PATH).unwrap();
 
     cx.config
         .expect(["rustup-init", "-y"])
@@ -101,8 +99,6 @@ info: default toolchain set to stable-[HOST_TUPLE]
 #[tokio::test]
 async fn proxies_are_relative_symlinks() {
     let cx = CliTestContext::new(Scenario::SimpleV2).await;
-    #[cfg(windows)]
-    let _path_guard = RegistryGuard::new(&USER_PATH).unwrap();
 
     cx.config
         .expect(["rustup-init", "-y"])
@@ -141,8 +137,6 @@ info: default toolchain set to stable-[HOST_TUPLE]
 #[tokio::test]
 async fn install_twice() {
     let cx = CliTestContext::new(Scenario::SimpleV2).await;
-    #[cfg(windows)]
-    let _path_guard = RegistryGuard::new(&USER_PATH).unwrap();
 
     cx.config.expect(["rustup-init", "-y"]).await.is_ok();
     cx.config.expect(["rustup-init", "-y"]).await.is_ok();
@@ -204,6 +198,28 @@ async fn uninstall_deletes_bins() {
     assert!(!rust_gdbgui.exists());
 }
 
+#[tokio::test]
+async fn uninstall_deletes_installed_toolchains() {
+    let cx = setup_empty_installed().await;
+    let path = cx.config.customdir.join("custom-1");
+    let path = path.to_string_lossy();
+    cx.config
+        .expect(["rustup", "toolchain", "link", "custom", &path])
+        .await
+        .is_ok();
+    cx.config
+        .expect(["rustup", "self", "uninstall", "-y"])
+        .await
+        .with_stderr(snapbox::str![[r#"
+...
+info: uninstalling toolchain custom
+info: toolchain custom uninstalled
+...
+"#]])
+        .is_ok();
+    assert!(!cx.config.rustupdir.join("toolchains").exists());
+}
+
 #[tokio::test]
 async fn uninstall_works_if_some_bins_dont_exist() {
     let cx = setup_empty_installed().await;
@@ -417,18 +433,25 @@ async fn update_overwrites_programs_display_version() {
     let version = env!("CARGO_PKG_VERSION");
 
     let cx = SelfUpdateTestContext::new(TEST_VERSION).await;
-    let _guard = RegistryGuard::new(&USER_RUSTUP_VERSION).unwrap();
+    let test_id = &cx.config.test_registry_id;
     cx.config
         .expect(["rustup-init", "-y", "--no-modify-path"])
         .await
         .is_ok();
 
     USER_RUSTUP_VERSION
-        .set(Some(&Value::from(PLACEHOLDER_VERSION)))
+        .set(
+            Some(&Value::from(PLACEHOLDER_VERSION)),
+            test_id,
+            CURRENT_USER,
+        )
         .unwrap();
     cx.config.expect(["rustup", "self", "update"]).await.is_ok();
     assert_eq!(
-        USER_RUSTUP_VERSION.get().unwrap().unwrap(),
+        USER_RUSTUP_VERSION
+            .get(test_id, CURRENT_USER)
+            .unwrap()
+            .unwrap(),
         Value::from(version)
     );
 }
diff --git a/tests/suite/cli_v2.rs b/tests/suite/cli_v2.rs
index 9b0ef8d4a3..b4ce3a998a 100644
--- a/tests/suite/cli_v2.rs
+++ b/tests/suite/cli_v2.rs
@@ -767,6 +767,51 @@ async fn install_override_toolchain_from_version() {
         .is_ok();
 }
 
+#[tokio::test]
+async fn install_with_default_flag() {
+    let cx = CliTestContext::new(Scenario::SimpleV2).await;
+    cx.config
+        .expect(["rustup", "default", "nightly"])
+        .await
+        .is_ok();
+    cx.config
+        .expect(["rustup", "toolchain", "install", "beta", "--default"])
+        .await
+        .is_ok();
+    cx.config
+        .expect(["rustc", "--version"])
+        .await
+        .with_stdout(snapbox::str![[r#"
+1.2.0 (hash-beta-1.2.0)
+
+"#]])
+        .is_ok();
+}
+
+#[tokio::test]
+async fn install_with_override_flag() {
+    let mut cx = CliTestContext::new(Scenario::SimpleV2).await;
+    let tempdir = tempfile::Builder::new().prefix("rustup").tempdir().unwrap();
+    cx.config
+        .expect(["rustup", "default", "nightly"])
+        .await
+        .is_ok();
+
+    let cx = cx.change_dir(tempdir.path());
+    cx.config
+        .expect(["rustup", "toolchain", "install", "beta", "--override"])
+        .await
+        .is_ok();
+    cx.config
+        .expect(["rustc", "--version"])
+        .await
+        .with_stdout(snapbox::str![[r#"
+1.2.0 (hash-beta-1.2.0)
+
+"#]])
+        .is_ok();
+}
+
 #[tokio::test]
 async fn override_overrides_default() {
     let mut cx = CliTestContext::new(Scenario::SimpleV2).await;
@@ -2422,7 +2467,8 @@ async fn test_warn_if_complete_profile_is_used() {
         .await
         .with_stderr(snapbox::str![[r#"
 ...
-warn: downloading with complete profile isn't recommended unless you are a developer of the rust language
+warn: downloading with the `complete` profile is deprecated
+help: consider switching to the `default` profile with `rustup set profile default`
 ...
 "#]])
         .is_err();
diff --git a/www/rustup.css b/www/rustup.css
index cc13ee6fb0..dbc04af2e8 100644
--- a/www/rustup.css
+++ b/www/rustup.css
@@ -214,11 +214,12 @@ hr {
 }
 
 div.copy-icon {
-    transform: translateX(3px);
+    transform: translateX(2px);
 }
 
 div.copy-icon svg {
     fill: var(--body-color);
+    display: block;
 }
 
 button.copy-button:hover svg {