setup.py

from setuptools import setup, Extension, find_packages

from distutils.command.build_ext import build_ext as _build_ext
from wheel.bdist_wheel import bdist_wheel as _bdist_wheel


class CTypesExtension(Extension):
    pass


class build_ext(_build_ext):
    def build_extension(self, ext):
        self._ctypes = isinstance(ext, CTypesExtension)
        return super().build_extension(ext)

    def get_export_symbols(self, ext):
        if self._ctypes:
            return ext.export_symbols
        return super().get_export_symbols(ext)

    def get_ext_filename(self, ext_name):
        if self._ctypes:
            return ext_name + ".so"
        return super().get_ext_filename(ext_name)




class bdist_wheel_abi_none(_bdist_wheel):
    def finalize_options(self):
        _bdist_wheel.finalize_options(self)
        self.root_is_pure = False

    def get_tag(self):
        python, abi, plat = _bdist_wheel.get_tag(self)
        return "py3", "none", plat


setup(
    name="spam",
    version="0.1.0",
    packages=["spam"],
    package_dir={"": "src"},
    ext_modules=[
        CTypesExtension(
            "spam.csumlib",
            ["src/spam/csumlib.c"],
        ),
    ],
    cmdclass={"build_ext": build_ext, "bdist_wheel": bdist_wheel_abi_none},
)