I maintain a library implemented mostly in python with some simple cpython extension modules for performance. Since you can't run unit tests against an extension module before you've built it, my Makefile invokes setup.py just to get things compiled:

  python setup.py build_ext --inplace

I don't see a valid replacement for this invocation, but fortunately, it's the only one.

When I include the library from a project that uses it, the same `pip install' command that brings the library in also performs all the compilation described by my setup.py.

All I'd need to move away from deprecated syntax entirely is a way to build the module when I'm testing it within it's own source directory. Until then I won't be changing anything.