I'm wondering what you would think about adding a new option to entirely disable the auto-loading of plugins though setuptools entrypoints, either through a command line argument or through an environment variable.

Test runs don't always run in isolated environments and there are some disruptive pytest plugins out there such as pytest-relaxed that will break test runs of projects that aren't made for it.

We get this problem in Gentoo when running some packages in test mode, as we can see in this issue. We're patching things around to make things work, but really, the most elegant way to solve this problem would be if we could somehow disable autoloading entirely and explicitly load required plugins for each package.

Would a PR that add this feature be welcome?