Only current answer: don't try it with setuptools if you're trying to build an independent .[whatevs] from numba code. Use cc.compile() at the end of your code, run it, and do whatever is necessary to make sure it talks to your c compiler correctly. On windows, Vis Studio works, run 'python yourfile.py' from the appropriate visual studio Native Tools Command Prompt. Getting cython to work from setuptools with your compiler doesn't automatically make numba work with it.