chore: minimal repro for crash

Author: GuillaumeLagrange

pyproject.toml

@@ -47,7 +47,7 @@ compat = [
 [tool.uv]
 # Python builds change with uv versions, and we are quite susceptible to that.
 # We pin uv to to make sure reproducibility is maintained for any contributor.
-required-version = "0.9.5"
+required-version = ">=0.9.5"
 
 [tool.uv.sources]
 pytest-codspeed = { workspace = true }

report.md

@@ -0,0 +1,51 @@
+# Segfault in `instrument_hooks_deinit` during Python shutdown
+
+## Issue
+
+CI job `tests (valgrind, 3.13, >=8.1.1)` crashes with exit code 139 (SIGSEGV) after all tests pass.
+The segfault occurs during Python's shutdown/GC phase, not during test execution.
+
+Failing CI run: https://github.com/CodSpeedHQ/pytest-codspeed/actions/runs/23649460934/job/68890119732
+
+## Root cause (suspected)
+
+`InstrumentHooks.__del__` calls `instrument_hooks_deinit()` via cffi during Python shutdown.
+When multiple `InstrumentHooks` instances are created (e.g. the xdist test loops 5 times, each creating a new instance), their destructors fire during GC at exit and crash — likely because the native library or cffi runtime is already partially torn down.
+
+## Stack trace (from CI)
+
+```
+Fatal Python error: Segmentation fault
+  File "plugin.py", line 148 in pytest_configure
+  ...
+  File "test_pytest_plugin_cpu_instrumentation.py", line 116 in test_pytest_xdist_concurrency_compatibility
+```
+
+## Minimal repro
+
+```python
+# repro.py
+import os
+os.environ["CODSPEED_ENV"] = "1"
+
+from pytest_codspeed.instruments.hooks import InstrumentHooks
+
+for i in range(5):
+    h = InstrumentHooks()
+    print(f"Created instance {i}: {h.instance}")
+
+del h
+print("Exiting...")
+```
+
+```
+uv run python repro.py
+# Segfaults at exit with code 139
+```
+
+## Key files
+
+- `src/pytest_codspeed/instruments/hooks/__init__.py` — `InstrumentHooks.__del__` calls `instrument_hooks_deinit`
+- `src/pytest_codspeed/instruments/hooks/build.py` — cffi bindings for the native library
+- `src/pytest_codspeed/instruments/analysis.py` — creates `InstrumentHooks` in `__init__`
+- `tests/test_pytest_plugin_cpu_instrumentation.py::test_pytest_xdist_concurrency_compatibility` — triggers the bug by creating 5 successive instances

repro.py

@@ -0,0 +1,11 @@
+import os
+os.environ["CODSPEED_ENV"] = "1"
+
+from pytest_codspeed.instruments.hooks import InstrumentHooks
+
+for i in range(5):
+    h = InstrumentHooks()
+    print(f"Created instance {i}: {h.instance}")
+
+del h
+print("Exiting...")

tests/test_pytest_plugin_cpu_instrumentation.py

@@ -110,7 +110,7 @@ def test_my_stuff(benchmark, i):
         """
     )
     # Run the test multiple times to reduce the chance of a false positive
-    ITERATIONS = 5
+    ITERATIONS = 2
     for i in range(ITERATIONS):
         with codspeed_env():
             result = pytester.runpytest("--codspeed", "-n", "128")