Importing fido2.hid causes Abort trap: 6 on macOS 13.6.5

[neverpanic]

:) cllang@cllang-mac:~$ python3.12 -c 'import fido2'
:) cllang@cllang-mac:~$ python3.12 -c 'import fido2.hid'
Abort trap: 6

Tested with fido2 1.1.3 and Python 3.12.2 from MacPorts on macOS 13.6.5 22G621.

The backtrace for the crash is

(lldb) thread backtrace
* thread #2, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
  * frame #0: 0x00007ff80d5c5196 libsystem_kernel.dylib`__pthread_kill + 10
    frame #1: 0x00007ff80d5fcee6 libsystem_pthread.dylib`pthread_kill + 263
    frame #2: 0x00007ff80d523b45 libsystem_c.dylib`abort + 123
    frame #3: 0x000000010313572e libffi.8.dylib`dlfree + 2991
    frame #4: 0x00000001031cf5e0 _ctypes.cpython-312-darwin.so`CThunkObject_dealloc + 41
    frame #5: 0x00000001007b2d3d Python`dictkeys_decref.llvm.16115435366937117356 + 151
    frame #6: 0x00000001007b5f1f Python`dict_dealloc + 247
    frame #7: 0x00000001031c8ce2 _ctypes.cpython-312-darwin.so`PyCData_clear + 93
    frame #8: 0x00000001031c9f09 _ctypes.cpython-312-darwin.so`PyCFuncPtr_clear + 353
    frame #9: 0x00000001031c94eb _ctypes.cpython-312-darwin.so`PyCFuncPtr_dealloc + 14
    frame #10: 0x00000001007e58e5 Python`subtype_dealloc + 798
    frame #11: 0x00000001007b2d3d Python`dictkeys_decref.llvm.16115435366937117356 + 151
    frame #12: 0x00000001007b660c Python`dict_tp_clear + 9
    frame #13: 0x00000001008e9cb9 Python`gc_collect_main.llvm.884759508876051100 + 1125
    frame #14: 0x00000001008e983f Python`_PyGC_CollectNoFail + 49
    frame #15: 0x00000001008be02d Python`finalize_modules.llvm.12581047115581953725 + 1437
    frame #16: 0x00000001008bd772 Python`Py_FinalizeEx + 188
    frame #17: 0x00000001008e8464 Python`Py_RunMain + 472
    frame #18: 0x00000001008e87d1 Python`Py_BytesMain + 42
    frame #19: 0x00007ff80d2a241f dyld`start + 1903

If I stub out the elif sys.platform.startswith("darwin") block in hid/__init__.py and replace the three functions with lambdas that do nothing, this crash does not occur, so it must be caused by something in fido2.hid.macos.

If I comment both REGISTERED_READ_CALLBACK and REMOVAL_CALLBACK in hid/macos.py, the crash no longer happens.

[dainnilsson]

Could you test with 1.1.2 and see if it was an issue there as well?

[neverpanic]

Yes, same situation: The crash is present, and it disappears if I comment REGISTERED_READ_CALLBACK and REMOVAL_CALLBACK.

[neverpanic]

More data points, if I do this with Apple's /usr/bin/python3 (3.9.6) in a virtualenv, it does not fail.
With MacPorts Python 3.11 in a virtualenv, it also does not fail.

Sounds like a change in Python 3.12?

[neverpanic]

Oh, and because I didn't mention it yet: This happens on shutdown – everything works fine until you end the program, at which point during cleanup and module unload it causes this error.