Remove setup_requires and tests_require and package_index

[jaraco]

It's time to remove easy_install and all the things it depends on, including setup_requires, tests_require, package_index.

Use of setup_requires has been discouraged for some time. Let's get it officially deprecated and removed.

[aragilar]

Is there some way to set the return values of get_requires_for_build_wheel and get_requires_for_build_sdist to replace usage of setup_requires (e.g. for dynamic dependencies which won't work under PEP 518)?

[jaraco]

There is not currently, but that seems like a good idea. Maybe file a feature request if there isn’t one already. I’d like to collect some cases and design options.

[anntzer]

Would it be possible for setup_requires removal to be postponed until after PEP660 support is implemented (including for non-pure-python packages, as requested in #2816 (comment))? Otherwise, there would be a gap during which there would be no way (well, other than pinning setuptools) to write editably-installable packages with build-time dependencies.
Thanks :)

[jaraco]

Would it be possible for setup_requires removal to be postponed until after PEP660 support is implemented (including for non-pure-python packages, as requested in #2816 (comment))? Otherwise, there would be a gap during which there would be no way (well, other than pinning setuptools) to write editably-installable packages with build-time dependencies.
Thanks :)

If you’re right, then yes. Editable installs are very important and there must be a transition to a working replacement.

In my testing, however, pip does install build-time dependencies including those specified for build wheel or build sdist, which resolves from setup requires. I’ll do some more testing and confirm again, but I believe setup-requires is honored for editable installs by that fall back to setup.py develop.

[anntzer]

Yes, setup_requires are currently honored (and installed if needed) by pip for editable installs. My fear is that setup_requires get removed from setuptools and therefore also by pip, with the intent of forcing the use of pyproject.toml to specify build-time dependencies; as far as I understand (but I may well be mistaken, please let me know in that case), pyproject.toml+setuptools is currently incompatible with editable installs.