The clang-build-ext extension builds Python extensions using a Clang compiler stack.
Either system LLVM/Clang or karellen-llvm-clang package can be used.
Beyond compiler the additional functionality is currently undocumented.
Add the following to the setup.py script:
from setuptools import setup
from karellen.clang_build_ext import ClangBuildExt, ClangBuildClib
...
setup(
..., 
cmdclass={"build_ext": ClangBuildExt,
          "build_clib": ClangBuildClib},)
)