Comment 8 for bug 1658169

Thanks for working on this! Just keep talking :)

Regarding the Cython error, it looks like you already installed Cython, which is needed to do a source build. I think it would be good to declare a sticky Cython version in requirements.txt, currently 0.25.2 for the 3.7.x release branch (and master). You should then pass "--with-cython" to "setup.py build_ext" to enable its usage.