CHORE: Flaky Tests - skip subprocess shutdown/teardown tests under QEMU and fix detection

[Gaurav Sharma (bewithgaurav)]

Work Item / Issue Reference

ADO Work Item: Fixed AB#47261

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Summary

the subprocess shutdown/teardown tests in test_013_SqlHandle_free_shutdown and test_024_context_manager_transaction intermittently segfault on the qemu-emulated linux arm64 CI legs and force reruns. the crash is a latent use-after-free in odbc handle-teardown ordering (an unclosed DBC handle finalized by gc at interpreter shutdown after the process-lifetime ENV handle is gone, so SQLFreeHandle touches freed ENV memory); it is benign on native hardware and only turns fatal under qemu's page reuse plus altered gc timing, which is why it is flaky and clears on rerun.

test-only, two changes:

• fix is_qemu_emulated() in conftest.py. the old check only matched CPU implementer 0x51, which never appears under multiarch/qemu-user-static (the emulated aarch64 process sees the x86_64 host's /proc/cpuinfo, which has no arm implementer field). it now flags an aarch64 process when cpuinfo advertises implementer 0x51 (qemu-system) or lacks the arm-only CPU implementer field entirely (qemu-user host passthrough); native arm64 and x86 stay unflagged. the existing test_013 skip was dead because of this and now takes effect.
• add a class-level skipif(QEMU) to test_024's TestContextManagerCommit (all 24 cases run the subprocess-teardown path).

the conftest docstring documents the underlying teardown-order uaf as the known-failure case. that root-cause bug is tracked separately and is unaffected by this skip; native legs still run these tests, so a regression there is not masked.

[github-actions]

📊 Code Coverage Report

🔥 Diff Coverage 100%

🎯 Overall Coverage 82%

📈 Total Lines Covered: 7368 out of 8963 📁 Project: mssql-python

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Diff: main...HEAD, staged and unstaged changes

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📋 Files Needing Attention

📉 Files with overall lowest coverage (click to expand)

mssql_python.pybind.logger_bridge.cpp: 59.2%
mssql_python.pybind.ddbc_bindings.h: 59.9%
mssql_python.pybind.logger_bridge.hpp: 70.8%
mssql_python.pybind.ddbc_bindings.cpp: 76.6%
mssql_python.__init__.py: 77.6%
mssql_python.row.py: 77.6%
mssql_python.ddbc_bindings.py: 79.6%
mssql_python.pybind.connection.connection_pool.cpp: 81.4%
mssql_python.pybind.connection.connection.cpp: 84.3%
mssql_python.logging.py: 85.5%

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[Copilot]

Pull request overview

This PR updates the Python test suite to avoid flaky subprocess shutdown/teardown crashes on QEMU-emulated Linux ARM64 CI, while keeping the same tests running on native hardware.

Changes:

• Fixes QEMU user-mode emulation detection in tests/conftest.py so existing QEMU-only skips actually trigger on the affected CI legs.
• Skips the entire subprocess-based context-manager transaction test class under QEMU to prevent intermittent SIGSEGVs.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
tests/test_024_context_manager_transaction.py	Adds a class-level skipif(QEMU) to avoid flaky subprocess teardown crashes under QEMU emulation.
tests/conftest.py	Updates is_qemu_emulated() logic to detect QEMU user-mode ARM64-on-x86_64 more reliably and documents the known-failure case.

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