fix: mark virtual workspace Cargo.toml manifests as skipped, not zero-node

[seonghobae]

Summary

• A Cargo.toml with only [workspace] (no [package]) legitimately declares no package node — this is by design and already handled (_parse_cargo returns None).
• However extract.py's Ruby: stable subset of files yields zero nodes in full-repo runs (0.9.6) — each extracts fine in isolation #1666 empty-source detector cannot distinguish "legitimately declared nothing" from "an extractor exists but silently produced nothing" and prints a persistent warning: N source file(s) produced zero nodes for every such manifest, on every run.
• _parse_cargo now reports workspace_only=True when [workspace] is present with no [package]; extract_package_manifest returns skipped=True in that case only (a manifest missing a name for any other reason still warns, since that IS unexplained).

Reproduction (evidence from downstream)

Reported downstream at ContextualWisdomLab/fast-mlsirm#1833: a fresh extract . --code-only --no-cluster run against a Cargo workspace root prints:

warning: 1 source file(s) produced zero nodes and are absent from the graph: Cargo.toml. ...(#1666)

on every run, even though the workspace-only manifest never had a package node to emit (the root only has [workspace], no [package]).

Test plan

• Added test_cargo_virtual_workspace_manifest_is_marked_skipped (RED before the fix, GREEN after) asserting skipped=True for a workspace-only manifest and skipped is not True for a manifest that is missing a name for any other reason.
• pytest tests/test_manifest_ingest.py — 14 passed.

Related upstream issues referenced by the downstream report: #1264 (Cargo manifest extractor), #2434 (TOML collection).

🤖 Generated with Claude Code

[graphify-labs]

Graphify reviewed this change.

Looks safe to merge — no coupling regressions and no blocking issues, checked against the code graph (not a self-assessment).

Formal verification. 1 change(s) alter behavior, breaking input(s) attached.

Behavior changes: \_match\_cited\_file changes behavior, here is the input that shows it.

The verifier found a concrete input on which \_match\_cited\_file behaves differently before and after the change. If that change is intended, ship it; if not, this is your bug.

Guarantee: This difference was REPRODUCED, the verifier actually ran both versions on that input and saw them disagree. It is real, not an artifact.

Evidence: On input \{"cited":"'\./'","doc\_file":"'\.mdx'","source\_files":"\{1, 2, 3\}"\}, the old code produced None but the new code produces raises AttributeError. Paste that input straight into a regression test.

---

Graphify review — findings

Marks Cargo virtual-workspace roots (a [workspace] table with no [package]) as skipped in extract_package_manifest, so their legitimate zero-node result no longer triggers extract.py's empty-source "produced zero nodes" warning on every run. A manifest missing a name for any other reason still returns unskipped and keeps warning, so genuinely malformed manifests aren't hidden.

No blocking issues surfaced. 2 lower-confidence candidates did not survive cross-model review.

Analysis details — impact, health, verification

Impact & health

Graphify review

Impact — 1552 functions depend on the 39 functions this change touches.

Health — this change adds coupling hotspots:

• new: extract() — 637 callers, 45 callees
• new: _rebuild_code() — 123 callers, 53 callees
• new: detect() — 112 callers, 15 callees
• new: dispatch_command() — 2 callers, 125 callees
• new: detect_incremental() — 23 callers, 7 callees
• new: _get_extractor() — 26 callers, 6 callees
• new: _is_sensitive() — 39 callers, 4 callees
• new: classify_file() — 43 callers, 3 callees
• …and 14 more — each is listed as a finding

Verification — 1552 functions in the blast radius were not formally verified this run (proofs are advisory here).

Gate & verification

graphify gate

PASS — objectively clean (no health regressions, tests not run — proofs not run this pass (advisory)). Grounded, not self-assessed.

Advisory (not blocking):

• verification_scope: 648 function(s) in the blast radius were not formally verified this run

Test selection

Test selection

15 of 283 test file(s) selected (5%) via static blast radius.

• tests/test_apm_fallback_version.py — impact
• tests/test_detect.py — impact
• tests/test_dotnet.py — impact
• tests/test_extract.py — impact
• tests/test_ignore_file_encoding.py — impact
• tests/test_incremental_mtime_collision.py — impact
• tests/test_languages.py — impact
• tests/test_manifest_ingest.py — impact, changed-test
• tests/test_manifest_tomli_required.py — impact
• tests/test_mcp_ingest.py — impact
• tests/test_out_dir_evidence.py — impact
• tests/test_pipeline.py — impact
• tests/test_stale_prune.py — impact
• tests/test_watch.py — impact
• tests/test_watch_manifest_location.py — impact

Selection is safe under the controlled-regression assumption; always-run tests + a periodic full run are the backstops. Advisory — it never changes the check verdict.

Formal verification

Behavior changes: \_match\_cited\_file changes behavior, here is the input that shows it.

The verifier found a concrete input on which \_match\_cited\_file behaves differently before and after the change. If that change is intended, ship it; if not, this is your bug.

Guarantee: This difference was REPRODUCED, the verifier actually ran both versions on that input and saw them disagree. It is real, not an artifact.

Evidence: On input \{"cited":"'\./'","doc\_file":"'\.mdx'","source\_files":"\{1, 2, 3\}"\}, the old code produced None but the new code produces raises AttributeError. Paste that input straight into a regression test.

Could not verify: Could not verify build\_from\_json.

The verifier did not have enough to check build\_from\_json, so it is saying so rather than guessing. No false assurance is the whole point.

Guarantee: No guarantee either way, this is an honest abstention, not a pass.

Note: Reason: no capturable inputs from the test suite; property tier: not verifiable: all 6 sampled inputs raised on both versions — the function never executed, so 'no divergence' would be vacuous (mostly NameError — names the real obstacle, not a sampling gap)

Could not verify: Could not verify prefix\_graph\_for\_global.

The verifier did not have enough to check prefix\_graph\_for\_global, so it is saying so rather than guessing. No false assurance is the whole point.

Guarantee: No guarantee either way, this is an honest abstention, not a pass.

Note: Reason: no capturable inputs from the test suite; property tier: not verifiable: all 200 sampled inputs raised on both versions — the function never executed, so 'no divergence' would be vacuous

Could not verify: Could not verify dispatch\_command.

The verifier did not have enough to check dispatch\_command, so it is saying so rather than guessing. No false assurance is the whole point.

Guarantee: No guarantee either way, this is an honest abstention, not a pass.

Note: Reason: no capturable inputs from the test suite; property tier: not verifiable: all 23 sampled inputs raised on both versions — the function never executed, so 'no divergence' would be vacuous (mostly SystemExit — names the real obstacle, not a sampling gap)

Could not verify: Could not verify extract\_elixir.

The verifier did not have enough to check extract\_elixir, so it is saying so rather than guessing. No false assurance is the whole point.

Guarantee: No guarantee either way, this is an honest abstention, not a pass.

Note: Reason: no capturable inputs from the test suite; property tier: parameter `path` is annotated `Path` — outside the synthesizable primitive/collection set

No difference found (not proven): No behavior difference found in \_code\_span\_mention (not a proof).

The verifier ran both versions of \_code\_span\_mention on many inputs and saw identical behavior every time. Strong evidence the change is safe, but evidence, not a proof.

Guarantee: Empirical: differential testing (both versions run on many generated inputs). A divergence on an untested input remains possible, so this is 'no counterexample found', not 'proven equivalent'.

Note: An input the sampler did not try could still differ.

Could not verify: Could not verify extract\_markdown.

The verifier did not have enough to check extract\_markdown, so it is saying so rather than guessing. No false assurance is the whole point.

Guarantee: No guarantee either way, this is an honest abstention, not a pass.

Note: Reason: no capturable inputs from the test suite; property tier: parameter `path` is annotated `Path` — outside the synthesizable primitive/collection set

Could not verify: Could not verify extract\_rust.

The verifier did not have enough to check extract\_rust, so it is saying so rather than guessing. No false assurance is the whole point.

Guarantee: No guarantee either way, this is an honest abstention, not a pass.

Note: Reason: no capturable inputs from the test suite; property tier: parameter `path` is annotated `Path` — outside the synthesizable primitive/collection set

Could not verify: Could not verify extract\_package\_manifest.

The verifier did not have enough to check extract\_package\_manifest, so it is saying so rather than guessing. No false assurance is the whole point.

Guarantee: No guarantee either way, this is an honest abstention, not a pass.

Note: Reason: no capturable inputs from the test suite; property tier: parameter `path` is annotated `Path` — outside the synthesizable primitive/collection set

Could not verify: Could not verify \_parse\_cargo.

The verifier did not have enough to check \_parse\_cargo, so it is saying so rather than guessing. No false assurance is the whole point.

Guarantee: No guarantee either way, this is an honest abstention, not a pass.

Note: Reason: no capturable inputs from the test suite; property tier: non-vacuity: domain too small (only 2 distinct inputs exercised, need 3) — 'no divergence' would be near-vacuous

No difference found (not proven): No behavior difference found in resolve\_markdown\_mentions (not a proof).

The verifier ran both versions of resolve\_markdown\_mentions on many inputs and saw identical behavior every time. Strong evidence the change is safe, but evidence, not a proof.

Guarantee: Empirical: differential testing (both versions run on many generated inputs). A divergence on an untested input remains possible, so this is 'no counterexample found', not 'proven equivalent'.

Note: An input the sampler did not try could still differ.

Could not verify: Could not verify resolve\_ruby\_member\_calls.

The verifier did not have enough to check resolve\_ruby\_member\_calls, so it is saying so rather than guessing. No false assurance is the whole point.

Guarantee: No guarantee either way, this is an honest abstention, not a pass.

Note: Reason: no capturable inputs from the test suite; property tier: non-vacuity: domain too small (only 1 distinct inputs exercised, need 3) — 'no divergence' would be near-vacuous

Could not verify: Could not verify \_rebuild\_code.

The verifier did not have enough to check \_rebuild\_code, so it is saying so rather than guessing. No false assurance is the whole point.

Guarantee: No guarantee either way, this is an honest abstention, not a pass.

Note: Reason: no capturable inputs from the test suite; property tier: parameter `watch_path` is annotated `Path` — outside the synthesizable primitive/collection set

Could not verify: Could not verify \_reconcile\_markdown\_links.

The verifier did not have enough to check \_reconcile\_markdown\_links, so it is saying so rather than guessing. No false assurance is the whole point.

Guarantee: No guarantee either way, this is an honest abstention, not a pass.

Note: Reason: no capturable inputs from the test suite; property tier: parameter `project_root` is annotated `Path` — outside the synthesizable primitive/collection set

· 22 more finding(s) on lines outside this diff (see the check run).