PEP 751: now with graphs!

[charliermarsh (Charlie Marsh)]

@pf_moore

And for what it’s worth, multiple environments per lockfile imposes another (IMO unwarranted) requirement, that everything is locked as one set - you can’t (for example) lock the docs group independently of the test group.

For what it’s worth, in uv, users can define groups that are known to be conflicting (i.e., mutually exclusive). So the entire project does not have to be lockable as a single unit. We solve them separately and then error install time if they try to install conflicting subsets.