[epistasis]

It seems that this information should cacheable after an invocation of setup.py, at least for an installation without any extras. And even with extras requested, perhaps.

Or is there any even greater hidden challenge from using setup.py?

[JaDogg]

setup.py can check the OS and pick necessary requirements. so it can have different dependencies in different OSes.

I've used it like this - https://github.com/JaDogg/pydoro/blob/b1b3de38ac15b9254ef1be...