Andrew G.

Good news: There's now a UCRT toolchain for MSYS2, which fixes the problem. pacman -S mingw-w64-ucrt-x86_64-toolchain This toolchain installs to MSYS2\ucrt64). To produce a working extension for a 64-bit Python (e.g. 3.8), put this directory on Windows PATH, then compile and link the SWIG wrapper. The necessary commands are given as comments in pysimcpp.h. From what I've read, the libstdc++ in MSYS2\Mingw64 is built against msvcrt - which is why C++ extensions linked to ucrt with the normal MinGW64...

Good news: There's now a UCRT toolchain for MSYS2, which fixes the problem. pacman -S mingw-w64-ucrt-x86_64-toolchain This toolchain installs to MSYS2\ucrt64). To produce a working extension for a 64-bit Python (e.g. 3.8), put this directory on Windows PATH, then compile and link the SWIG wrapper. From what I've read, the libstdc++ in MSYS2\Mingw64 is built against msvcrt - which is why extensions linked to ucrt with the normal MinGW64 toolchain crash.

Good news: There's now a UCRT toolchain for MSYS2, which fixes the problem. pacman -S mingw-w64-ucrt-x86_64-toolchain This toolchain installs to MSYS2\ucrt64). From what I've read, the libstdc++ in MSYS2\Mingw64 is built against msvcrt - which is why extensions linked to ucrt crashed.

Good news: There's now a UCRT toolchain for MSYS2, which fixes the problem. pacman -S mingw-w64-ucrt-x86_64-toolchain This toolchain installs to MSYS22\ucrt64). From what I've read, the libstdc++ in MSYS2\Mingw64 is built against msvcrt - which is why extensions linked to ucrt crashed.

Did a bit more probing and identified exception: Heap Corruption Exception 0xC0000374 C:\PySimcpp>c:\python38_x64\python -q -X faulthandler import _pysimcpp Windows fatal exception: code 0xc0000374 Current thread 0x00000bd4 (most recent call first): File "<frozen importlib._bootstrap="">", line 219 in _call_with_frames_removed File "<frozen importlib._bootstrap_external="">", line 1101 in create_module File "<frozen importlib._bootstrap="">", line 556 in module_from_spec File "<frozen importlib._bootstrap="">",...

Did a bit more probing and identified exception: Heap Corruption Exception 0xC0000374 C:\PySimcpp>c:\python38_x64\python -q -X faulthandler import _pysimcpp Windows fatal exception: code 0xc0000374 Current thread 0x00000bd4 (most recent call first): File "<frozen importlib._bootstrap="">", line 219 in _call_with_frames_removed File "<frozen importlib._bootstrap_external="">", line 1101 in create_module File "<frozen importlib._bootstrap="">", line 556 in module_from_spec File "<frozen importlib._bootstrap="">",...

I've also tried building the extension for 32-bit Python 3.8 (CPython) on Windows (also linking against ucrtbase). I still a crash when the extension is imported. The examples attached work correctly on a 64-bit Ubuntu system with Python 3.6. Andrew.

SWIG C++ Python 64-bit extensions for working MinGW64 GCC 9.2