PEP 517 and projects that can't install via wheels

[jdemeyer (Jeroen Demeyer)]

@takluyver

If your package is a counterexample ( setup.py install works but setup.py bdist_wheel doesn’t), please share details!

pip install and setup.py bdist_wheel treat install_requires differently. See the discussion at Install install_requires before running python setup.py bdist_wheel · Issue #6193 · pypa/pip · GitHub and Support for build-and-run-time dependencies