test_tracemalloc: test_tracemalloc_track_race() crashs on GHA iOS CI · Issue #150485 · python/cpython · GitHub

Crash report

iOS: https://github.com/python/cpython/actions/runs/26457870719/job/77897032289?pr=150441

This issue is likely the same as issue gh-143143, but I'm not 100% sure so I created a separated issue.

    0:11:19 load avg: 2.79 [435/505] test_tracemalloc
  Fatal Python error: Segmentation fault
  
  Current thread 0x0000000322193000 (most recent call first):
  
  Thread 0x0000000321187000 (most recent call first):
  
  Thread 0x000000032017b000 (most recent call first):
  
  (...)
  
  Thread 0x00000003100bb000 (most recent call first):
  
  <freed thread state>
  
  Current thread's C stack trace (most recent call first):
    Binary file "/Users/runner/work/cpython/cpython/cross-build/iOS-testbed.1779809388208/DerivedData/Build/Products/Debug-iphonesimulator/Python.framework/Python", at _Py_DumpStack+0x44 [0x102407804]
    Binary file "/Users/runner/work/cpython/cpython/cross-build/iOS-testbed.1779809388208/DerivedData/Build/Products/Debug-iphonesimulator/Python.framework/Python", at faulthandler_fatal_error+0x264 [0x10241e4a0]
    Binary file "/usr/lib/system/libsystem_platform.dylib", at _sigtramp+0x34 [0x100a6f7e0]
    Binary file "/Users/runner/work/cpython/cpython/cross-build/iOS-testbed.1779809388208/DerivedData/Build/Products/Debug-iphonesimulator/Python.framework/Python", at PyGILState_Ensure+0xf8 [0x1023eab50]
    Binary file "/Users/runner/work/cpython/cpython/cross-build/iOS-testbed.1779809388208/DerivedData/Build/Products/Debug-iphonesimulator/Python.framework/Python", at PyGILState_Ensure+0xf8 [0x1023eab50]
    Binary file "/Users/runner/work/cpython/cpython/cross-build/iOS-testbed.1779809388208/DerivedData/Build/Products/Debug-iphonesimulator/Python.framework/Python", at tracemalloc_alloc+0xa8 [0x1024097a4]
    Binary file "/Users/runner/work/cpython/cpython/cross-build/iOS-testbed.1779809388208/DerivedData/Build/Products/Debug-iphonesimulator/Python.framework/Python", at PyGILState_Ensure+0x58 [0x1023eaab0]
    Binary file "/Users/runner/work/cpython/cpython/cross-build/iOS-testbed.1779809388208/DerivedData/Build/Products/Debug-iphonesimulator/Python.framework/Python", at PyTraceMalloc_Track+0x34 [0x1024088ec]
    Binary file "/Users/runner/Library/Developer/CoreSimulator/Devices/D3F1CE55-196D-4DC8-9D1F-6D2D3AB3D118/data/Containers/Bundle/Application/130788EC-7B24-4534-8FF0-89C57EC65B80/iOSTestbed.app/Frameworks/_testcapi.framework/_testcapi", at tracemalloc_track_race_thread+0x20 [0x106f251b0]
    (...)
  
  Extension modules: _testcapi, _testinternalcapi, _testlimitedcapi, _testmultiphase, _testbuffer, _ctypes_test, xxsubtype, _testsinglephase_basic_wrapper, _testsinglephase_basic_copy, _testsinglephase_with_reinit, _testsinglephase_with_state, _test_non_isolated, _test_shared_gil_only, _test_no_multiple_interpreter_slot, _testsinglephase (total: 15)
  
  Restarting after unexpected exit, crash, or test timeout in -[TestbedTests testPython]; summary will include totals from previous launches.

Based on the investigation in #143143, I think we should change the test itself, starting or stopping tracemalloc is not safe at runtime and won't be safe because it affects raw allocator as well which is not synchronized.

The test does also crash randomly on Android. Example on aarch64 Android 3.13: https://buildbot.python.org/#/builders/1590/builds/1395

The traceback starts with test_tracemalloc_track_race():

0:09:33 [413/481] test_tracemalloc
W/native.stderr: exiting due to SIG_DFL handler for signal 11, ucontext 0x732c549e20
F/libc: exiting due to SIG_DFL handler for signal 11, ucontext 0x732c549e20
W/native.stderr: Fatal Python error: 
W/native.stderr: Aborted
W/native.stderr: 
W/native.stderr: Thread 0x
W/native.stderr: 0000007338aff4f8
W/native.stderr:  (most recent call first):
W/native.stderr:   File 
W/native.stderr: "
W/native.stderr: /data/user/0/org.python.testbed/files/python/lib/python3.13/test/test_tracemalloc.py
W/native.stderr: "
W/native.stderr: , line 
W/native.stderr: 1119
W/native.stderr:  in 
W/native.stderr: test_tracemalloc_track_race
W/native.stderr: 
W/native.stderr:   File 
W/native.stderr: "
W/native.stderr: /data/user/0/org.python.testbed/files/python/lib/python3.13/unittest/case.py
W/native.stderr: "
W/native.stderr: , line 
W/native.stderr: 606
W/native.stderr:  in 
W/native.stderr: _callTestMethod
W/native.stderr: 
W/native.stderr:   File 
W/native.stderr: "
W/native.stderr: /data/user/0/org.python.testbed/files/python/lib/python3.13/unittest/case.py
W/native.stderr: "
W/native.stderr: , line 
W/native.stderr: 651
W/native.stderr:  in 
W/native.stderr: run
W/native.stderr: 
W/native.stderr:   File 
W/native.stderr: "
W/native.stderr: /data/user/0/org.python.testbed/files/python/lib/python3.13/unittest/case.py
W/native.stderr: "
W/native.stderr: , line 
W/native.stderr: 707
W/native.stderr:  in 
W/native.stderr: __call__
W/native.stderr: 
W/native.stderr:   File 
W/native.stderr: "
W/native.stderr: /data/user/0/org.python.testbed/files/python/lib/python3.13/unittest/suite.py
W/native.stderr: "
W/native.stderr: , line 
W/native.stderr: 122
W/native.stderr:  in 
W/native.stderr: run
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/unittest/suite.py", line 84 in __call__
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/unittest/suite.py", line 122 in run
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/unittest/suite.py", line 84 in __call__
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/unittest/runner.py", line 240 in run
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/single.py", line 57 in _run_suite
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/single.py", line 37 in run_unittest
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/single.py", line 135 in test_func
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/single.py", line 91 in regrtest_runner
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/single.py", line 138 in _load_run_test
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/single.py", line 181 in _runtest_env_changed_exc
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/single.py", line 266 in _runtest
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/single.py", line 310 in run_single_test
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/main.py", line 371 in run_test
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/main.py", line 401 in run_tests_sequentially
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/main.py", line 551 in _run_tests
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/main.py", line 586 in run_tests
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/main.py", line 767 in main
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/libregrtest/main.py", line 775 in main
  File "/data/user/0/org.python.testbed/files/python/lib/python3.13/test/__main__.py", line 2 in <module>
  File "<frozen runpy>", line 88 in _run_code
  File "<frozen runpy>", line 203 in _run_module_as_main
W/native.stderr: Extension modules: 
W/native.stderr: _testcapi
W/native.stderr: , _testinternalcapi, _testlimitedcapi, _testbuffer, _ctypes_test
W/native.stderr: , xxsubtype, _testexternalinspection
W/native.stderr: , _testsinglephase_basic_wrapper, _testsinglephase_basic_copy, _testsinglephase_with_reinit, _testsinglephase_with_state, _test_non_isolated, _test_shared_gil_only, _test_no_multiple_interpreter_slot, _testmultiphase
W/native.stderr:  (total: 15)
F/libc: Fatal signal 6 (SIGABRT), code -6 (SI_TKILL) in tid 9309 (.python.testbed), pid 1638 (.python.testbed)

test_tracemalloc: test_tracemalloc_track_race() crashs on GHA iOS CI · Issue #150485 · python/cpython · GitHub

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test_tracemalloc: test_tracemalloc_track_race() crashs on GHA iOS CI #150485

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test_tracemalloc: test_tracemalloc_track_race() crashs on GHA iOS CI · Issue #150485 · python/cpython · GitHub

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test_tracemalloc: test_tracemalloc_track_race() crashs on GHA iOS CI #150485

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kumaraditya303 commented on Jun 1, 2026

vstinner commented on Jun 2, 2026

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