So, just for clarity, is there another approved mechanism for distributing an extension that just happens to act as a (Python version specific) C support library? I've wanted to be able to build a library (static or dynamic) that is installed to lib/pythonX.Y/site-packages so it can be found by other extensions that use it without them having to ship a copy themselves.

The best solution I found was building and installing untagged extensions with pip; the extension features weren't actually used for anything but unittesting the library, but making it an extension meant it got installed to the Python version specific site-packages.

If untagged extensions aren't just old-fashioned, but banned, my use case is broken, and I've been completely unable to find a decent, non-Cython based, setup.py based pattern for building a C library that provides wrappers for Python API calls (and therefore must target specific Python versions).