Take this setup.py that implements setup requirements (requirements needed for setup.py itself to run) https://bitbucket.org/dholth/setup-requires/src/tip/setup.py
Require your new build system using that mechanism, by mentioning it in setup.cfg Then instead of calling setup() from setuptools at the bottom, emulate the setup.py build system interface documented at http://pip.readthedocs.org/en/stable/reference/pip_install/#build-system-interface to invoke new build system. Check to make sure whether pip accepts .dist-info when calling the egg_info command. Then write a command for new build system that adds the shim setup.py to an sdist. Now you have a setup.py that can download and install new-build-system and interoperate with pip, without having to change pip at all.
_______________________________________________ Distutils-SIG maillist - [email protected] https://mail.python.org/mailman/listinfo/distutils-sig
