The Packaging summit topic PyPA governance is probably relevant here.
My thoughts (as they relate to this specific issue) as as follows: The levels of decision making for something like this are:
- Whatever the pip developers involved in the discussion, and especially the person writing the PR, think is best.
- The consensus of the pip developers as a group.
- The PyPA as a whole
- Standards-level discussion
Getting pip developer consensus is a matter of availability (for example, @dstufft hasn’t participated in this issue yet) but once enough of us get involved, the majority view is usually reasonably easy to identify. Ideally, there shouldn’t ever be any need to go beyond this for any other reason than the pip devs asking for a decision from the PyPA - I hope we don’t ever reach a point where we need a process for users to ask the PyPA to override the decisions of a project’s owners 
The problem is that there is no PyPA decision making process at the moment - there’s not even an easy to identify list of who is in the PyPA in order to take their views into consideration. So the decision here has to reside with the pip developers.
So I guess the question is, what is the pip developers’ consensus (taking into account the feedback here and on the tracker)? I was in favour of the solution @cjerdonek implemented (as, I assume, was he 
) but both of us have said we’d be happy to accept an alternative decision. @pradyunsg and @xafer have both expressed the view that -e should imply --no-use-pep517 (although there’s still the details to be worked out - this all started because of "conflict with the backend dependencies" error running pip install in editable mode with pyproject.toml / PEP-517 enabled project · Issue #6314 · pypa/pip · GitHub, so we can’t just revert without taking a view on what we do about that issue).
I’d say that so far, pip-dev consensus is in favour of -e implying --no-use-pep517. So if we assume that, what are the next steps?
- Someone needs to review Restore pyproject.toml handling to its version 19.0.3 state by cjerdonek · Pull Request #6449 · pypa/pip · GitHub
- Someone needs to look at how we address "conflict with the backend dependencies" error running pip install in editable mode with pyproject.toml / PEP-517 enabled project · Issue #6314 · pypa/pip · GitHub again
- All of this needs to be implemented and merged.
- We need to cut a bugfix release
I don’t honestly have the time over the next couple of weeks to do any of this - and I know that PyCon is coming up, so I suspect time is short for others as well. It might be nice, though, if we could set some sort of realistic expectation for the people waiting for this as to when we’d hope to have a fixed release out (it’s hard to get the decisions made when people are looking for a release in a matter of hours 
).