Vendoring Updates: Nov 2020 (round 2)

[pradyunsg]

Fixes #9011
Fixes #9077
Fixes #9138

This has been quite a month.

[pradyunsg]

Looks like we made a mistake in packaging.tags for MacOS tags. :)

[pradyunsg]

Here's the plan to deal with the failing test here: marking it as xfail right now, getting concensus on the right fix upstream and implementing whatever that fix is in a future release. :)

The behavior that we're breaking here is specifically that anyone specifying intel as their architecture through pip's CLI/configuration/env-vars will no longer get x86_64 and i386 wheels during installation. intel is a universal CPU arch that Python uses to denote binaries that work on both Intel CPU architectures on MacOS. Notably, this does not affect anyone using intel wheels even -- those architectures get detected as x86_64 or i386 and those are correctly handled to be compatible with intel wheels. Anyone affected by this can set their CPU architecture to be whichever on is appropriate for their systems (either x86_64 or i386).

puts on release manager hat

I imagine that there's very few people doing this, so it's OK to mark this as a known degradation in behaviour for right now. It is a significantly smaller problem than binary wheels not working properly for most MacOS Big Sur users. It's OK to get this into pip 20.3 -- but we should make a fix upstream or in our code "soon" for this OR... decide that the multi-arch uses specific-arch thing on MacOS isn't something we wanna support. All that, is post 20.3 though. If we get a fix, that can be a bugfix release of pip 20.3.

takes off release manager hat

Phew. :)