Python Crashes with Windows fatal exception: access violation when trying to load a pybind11 module

[eschan145]

Hello all,

I've attempted to use pybind11 on a Windows machine with g++:

g++ -ID:/a/_temp/msys64/mingw64/include/python3.12 -c src/util.cpp -o src/util.o -std=c++20
g++ -shared -ID:/a/_temp/msys64/mingw64/include/python3.12 -LD:/a/_temp/msys64/mingw64/lib src/util.o -lpython3.12 -o src/util.pyd

However, when I tried to import the generated pyd module in my Python code with a simple import util, Python crashes silently, without giving an error. I've specified DLLs with os.add_dll_directory(). I've also used faulthandler.enable() to try to see what is going on, as there is no error output and Python crashes mysteriously. This is what is spat out by fauthandler before the program finishes:

Windows fatal exception: access violation

Current thread 0x0000ae5c (most recent call first):
  File "<frozen importlib._bootstrap>", line 488 in _call_with_frames_removed
  File "<frozen importlib._bootstrap_external>", line 1289 in create_module
  File "<frozen importlib._bootstrap>", line 813 in module_from_spec
  File "<frozen importlib._bootstrap>", line 921 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1331 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1360 in _find_and_load

I doubt the issue is with my code, and rather the environment or my compilation command — running any of the pybind11 examples has the same error.

It's also unlikely that this is due to missing dependencies, as I ran into the issue The specified module could not be found and fixed it by using os.add_dll_directory.

Thanks for your help in advance.

[zhanghq-chn]

I had a very similar problem on my Mac, using CPython C API. The faulthandler spits out basically the same thing.