Source: openmpi Followup-For: Bug #995150 gdb on amd64 run locally confirms the segfault, running test_io.py alone. Refines the problem to MPIOI_File_iwrite_all in mca_io_romio321.so
$ gdb python3 (gdb) run -m pytest test_io.py Starting program: /usr/bin/python3 -m pytest test_io.py [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [New Thread 0x7ffff3f2b640 (LWP 3398120)] ... Thread 1 "python3" received signal SIGSEGV, Segmentation fault. 0x0000000000000000 in ?? () (gdb) bt #0 0x0000000000000000 in ?? () #1 0x00007fffad13ea84 in MPIOI_File_iwrite_all () from /usr/lib/x86_64-linux-gnu/openmpi/lib/openmpi3/mca_io_romio321.so #2 0x00007fffad13ebd3 in mca_io_romio_dist_MPI_File_iwrite_all () from /usr/lib/x86_64-linux-gnu/openmpi/lib/openmpi3/mca_io_romio321.so #3 0x00007fffad13c4c3 in mca_io_romio321_file_iwrite_all () from /usr/lib/x86_64-linux-gnu/openmpi/lib/openmpi3/mca_io_romio321.so #4 0x00007ffff3c86b4c in PMPI_File_iwrite_all () from /lib/x86_64-linux-gnu/libmpi.so.40 #5 0x00007ffff3e80d0c in __pyx_pf_6mpi4py_3MPI_4File_62Iwrite_all (__pyx_v_buf=<optimized out>, __pyx_v_self=0x7fffacf8db40) at src/mpi4py.MPI.c:159094 #6 __pyx_pw_6mpi4py_3MPI_4File_63Iwrite_all (__pyx_v_self=<mpi4py.MPI.File at remote 0x7fffacf8db40>, __pyx_args=__pyx_args@entry=(<array.array at remote 0x7fffad57c2f0>,), __pyx_kwds=__pyx_kwds@entry=0x0) at src/mpi4py.MPI.c:27957 #7 0x000000000052b141 in method_vectorcall_VARARGS_KEYWORDS (func=<optimized out>, args=0x1461818, nargsf=<optimized out>, kwnames=0x0) at ../Objects/descrobject.c:346 #8 0x00000000005127fb in _PyObject_VectorcallTstate (kwnames=0x0, nargsf=<optimized out>, args=0x1461818, callable=<method_descriptor at remote 0x7ffff3f073b0>, tstate=0x968fb0) at ../Include/cpython/abstract.h:118 #9 PyObject_Vectorcall (kwnames=0x0, nargsf=<optimized out>, args=0x1461818, callable=<method_descriptor at remote 0x7ffff3f073b0>) at ../Include/cpython/abstract.h:127 #10 call_function (kwnames=0x0, oparg=<optimized out>, pp_stack=<synthetic pointer>, tstate=0x968fb0) at ../Python/ceval.c:5075 #11 _PyEval_EvalFrameDefault (tstate=<optimized out>, f=<optimized out>, throwflag=<optimized out>) at ../Python/ceval.c:3504 #12 0x00000000005291c3 in _PyEval_EvalFrame (throwflag=0, f=Frame 0x1461640, for file /projects/python/build/mpi4py/test/test_io.py, line 306, in testIReadIWriteAll (self=<TestIOSelf(_testMethodName='testIReadIWriteAll', _outcome=<_Outcome(expecting_failure=False, result=<TestCaseFunction(keywords=<NodeKeywords(node=<...>, parent=<UnitTestCase(keywords=<NodeKeywords(node=<...>, parent=<Module(keywords=<NodeKeywords(node=<...>, parent=<Session(keywords=<NodeKeywords(node=<...>, parent=None, _markers={'mpi4py': True}) at remote 0x7fffb69c0850>, own_markers=[], extra_keyword_matches=set(), testsfailed=1, testscollected=28, shouldstop=False, shouldfail=False, trace=<TagTracerSub(root=<TagTracer(_tags2proc={}, _writer=None, indent=0) at remote 0x7ffff7865be0>, tags=('collection',)) at remote 0x7fffb69c0910>, startdir=<LocalPath(strpath='/projects/python/build/mpi4py/test') at remote 0x7fffb69c0550>, _initialpaths=frozenset({<LocalPath(strpath='/projects/python/build/mpi4py/test/test_io.py') at remote 0x7fffb69dfc10>}), _bestrelpathcache=<_best...(truncated), tstate=0x968fb0) at ../Include/internal/pycore_ceval.h:40 -- System Information: Debian Release: bookworm/sid APT prefers unstable APT policy: (500, 'unstable'), (1, 'experimental') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 5.10.0-8-amd64 (SMP w/8 CPU threads) Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8), LANGUAGE=en_AU:en Shell: /bin/sh linked to /usr/bin/dash Init: systemd (via /run/systemd/system) LSM: AppArmor: enabled