Release 0.640 planning

[gvanrossum]

I am the release manager for mypy 0.640. I plan to cut the release branch right now (Oct 5) and do the release in a week (Oct 12).

If there are PRs that are low-risk and high-value that ought to go into this release please mention them here and I'll see if they can be cherry-picked.

[ilevkivskyi]

I think we should decide what to do about #5738, because technically it is a regression. Possible options are:

• Don't care about this for now, it is minor and is caused by an old bug exposed by a fix to another issue.
• Implement a simple fix (unfortunately I don't have one yet, sorry, but it should not be hard) just to avoid the false positive.
• Revert the switch from all to invariant instance contexts.

[gvanrossum]

Release branch created: https://github.com/python/mypy/tree/release-0.640

It's currently identical to master -- the last commit is "Fix infinite loop on corrupted fine-grained cache (#5739)".

Anything that we decide should go into this release will be cherry-picked.

[gvanrossum]

I went through all of the motions of the release, but within minutes a regression was found (#5784) so I had to withdraw the release. There will be a new one Monday.

[msullivan]

0.641 got released a while ago