I have no problem compiling my extension under Linux and MacOS. Under Windows, I get a lot of
Error LNK2001: unresolved external symbol PyErr_SetObject and so on. I post the part of my setup.py about the C Extension: extra_compile_args = ["-DPY_SSIZE_T_CLEAN", "-DPy_BUILD_CORE"] undef_macros = [] setuptools.Extension( ext1_fullname, sources = cpython_sources, include_dirs = cpython_include_dirs, extra_compile_args = extra_compile_args, undef_macros = undef_macros, ) Here is the full code: https://github.com/Marco-Sulla/python-frozendict/blob/master/setup.py Steps to reproduce: I installed python3.10 and VS compiler on my Windows 10 machine, then I created a venv, activated it, run pip install -U pip setuptools wheel and then python setup.py bdist_wheel -- https://mail.python.org/mailman/listinfo/python-list