mcp(test[middleware]): Fix caplog double-capture on pytest 9.1.0

CHANGES

@@ -6,6 +6,12 @@
 _Notes on upcoming releases will be added here_
 <!-- END PLACEHOLDER - ADD NEW CHANGELOG ENTRIES BELOW THIS LINE -->
 
+### Development
+
+**Minimum `pytest>=9.1.0`**
+
+The dev and test dependency groups now require pytest 9.1.0 or newer. (#83)
+
 ## libtmux-mcp 0.1.0a14 (2026-06-14)
 
 libtmux-mcp 0.1.0a14 adds tier-aware tool batching. {tooliconl}`call-readonly-tools-batch`, {tooliconl}`call-mutating-tools-batch`, and {tooliconl}`call-destructive-tools-batch` run an ordered list of existing MCP tools in a single call and return a per-operation result for each, preserving every nested tool's own structured output. Each wrapper caps the safety tier of the calls it will make — regardless of the server's `LIBTMUX_SAFETY` tier — and `on_error` selects stop-at-first-failure or continue-and-report handling. Aggregate results stay within the server's response limit.

pyproject.toml

@@ -64,7 +64,7 @@ dev = [
   # Testing
   "typing-extensions; python_version < '3.11'",
   "gp-libs",
-  "pytest",
+  "pytest>=9.1.0",  # >=9.1.0 attaches caplog to non-propagating loggers; see test_middleware
   "pytest-rerunfailures",
   "pytest-mock",
   "pytest-watcher",
@@ -91,7 +91,7 @@ docs = [
 testing = [
   "typing-extensions; python_version < '3.11'",
   "gp-libs",
-  "pytest",
+  "pytest>=9.1.0",  # >=9.1.0 attaches caplog to non-propagating loggers; see test_middleware
   "pytest-rerunfailures",
   "pytest-mock",
   "pytest-watcher",

tests/test_middleware.py

@@ -448,16 +448,13 @@ def test_send_keys_batch_schema_validation_redacts_inputs(
     secret: str,
     expected_fragments: tuple[str, ...],
     caplog: pytest.LogCaptureFixture,
-    monkeypatch: pytest.MonkeyPatch,
 ) -> None:
     """Malformed batch schema errors do not echo raw key payloads."""
     from fastmcp import Client
 
     from libtmux_mcp.server import build_mcp_server
 
     assert test_id
-    for logger_name in ("fastmcp", "fastmcp.server.server", "fastmcp.errors"):
-        monkeypatch.setattr(logging.getLogger(logger_name), "propagate", True)
 
     async def _call() -> t.Any:
         async with Client(build_mcp_server()) as client:
@@ -1109,7 +1106,6 @@ def test_tool_error_result_logs_at_error_log_level(
     expected_level: int,
     message_fragment: str,
     caplog: pytest.LogCaptureFixture,
-    monkeypatch: pytest.MonkeyPatch,
 ) -> None:
     """``_log_error`` honors ``log_level``: WARNING expected, ERROR not.
 
@@ -1127,10 +1123,10 @@ def test_tool_error_result_logs_at_error_log_level(
     """
     from fastmcp import Client
 
-    # fastmcp's logger doesn't propagate to root (rich handler);
-    # re-enable propagation so caplog sees the records.
-    monkeypatch.setattr(logging.getLogger("fastmcp"), "propagate", True)
-
+    # fastmcp's logger is non-propagating (rich handler); pytest >=9.1.0
+    # attaches caplog directly to it. ``fastmcp.errors`` records reach
+    # caplog by propagating up to ``fastmcp`` — re-enabling propagation
+    # to root would then double-capture each emit (``fastmcp`` + root).
     probe = _error_probe_server()
 
     async def _call() -> None:

tests/test_utils.py

@@ -914,18 +914,13 @@ def test_map_exception_operator_faults_stay_at_error(raised: Exception) -> None:
 
 def test_expected_tool_error_logs_warning_through_server(
     caplog: pytest.LogCaptureFixture,
-    monkeypatch: pytest.MonkeyPatch,
 ) -> None:
     """Fastmcp's server-layer error log honors ``ExpectedToolError.log_level``.
 
     Uses a minimal FastMCP instance (no middleware stack) so the
     assertion isolates fastmcp's own ``Error calling tool`` record —
     the project middleware's log behavior is covered in
     ``test_middleware.py``.
-
-    fastmcp sets ``propagate = False`` on its logger (it installs a
-    rich handler instead), which hides records from caplog's
-    root-logger handler — re-enable propagation for the test.
     """
     import asyncio
     import logging
@@ -934,8 +929,6 @@ def test_expected_tool_error_logs_warning_through_server(
 
     from libtmux_mcp._utils import ExpectedToolError
 
-    monkeypatch.setattr(logging.getLogger("fastmcp"), "propagate", True)
-
     probe = FastMCP(name="probe")
 
     @probe.tool