[Free Threading] test_opcache: test_binary_subscr_list_int(): list_get_item_ref: Assertion `cap != -1 && cap >= size' failed#127521
Description
test_binary_subscr_list_int() does crash randomly with an assertion error if Python is built with --disable-gil:
$ ./python -m test test_opcache -v -m test_binary_subscr_list_int -j10 -F (...) test_binary_subscr_list_int (test.test_opcache.TestRacesDoNotCrash.test_binary_subscr_list_int) ... python: Objects/listobject.c:342: list_get_item_ref: Assertion `cap != -1 && cap >= size' failed. Fatal Python error: Aborted Thread 0x00007f244350f6c0 (most recent call first): File "/home/vstinner/python/main/Lib/test/test_opcache.py", line 638 in write File "/home/vstinner/python/main/Lib/threading.py", line 992 in run File "/home/vstinner/python/main/Lib/threading.py", line 1041 in _bootstrap_inner File "/home/vstinner/python/main/Lib/threading.py", line 1012 in _bootstrap Thread 0x00007f2443d106c0 (most recent call first): File "/home/vstinner/python/main/Lib/test/test_opcache.py", line 639 in write File "/home/vstinner/python/main/Lib/threading.py", line 992 in run File "/home/vstinner/python/main/Lib/threading.py", line 1041 in _bootstrap_inner File "/home/vstinner/python/main/Lib/threading.py", line 1012 in _bootstrap Current thread 0x00007f2451be5740 (most recent call first): File "/home/vstinner/python/main/Lib/test/test_opcache.py", line 632 in read File "/home/vstinner/python/main/Lib/test/test_opcache.py", line 586 in assert_races_do_not_crash File "/home/vstinner/python/main/Lib/test/test_opcache.py", line 22 in wrapper File "/home/vstinner/python/main/Lib/test/test_opcache.py", line 642 in test_binary_subscr_list_int (...) Extension modules: _testinternalcapi (total: 1) Bug seen on macOS CI, and reproduced on Linux.