GeezerVison

@hugovk - after a few false starts, I think this is ready for review!

The macOS tests passed, but I'm going to manually re-run them to see how they behave on subsequent runs.

Of the three runs, I looked at the just the macos-14 jobs.

Each run has two jobs running in parallel (free-threaded and regular). For the first run, there's no cache, as expected.

At the end of the first run, they try and save the cache. One succeeds. The other doesn't, because "another job may be creating this cache". Fair enough.

For the second run, I would have expected the cache to be there, but both said it wasn't found, even though they used the same key as the first run. That is odd. At the end of the run, one job saves the cache, and the other tries but can't.

For the third run, the same thing happens -- no cache found, then one saves, one doesn't.

I wonder what was going on? Not enough time between runs?

For the second run, I would have expected the cache to be there, but both said it wasn't found

It looks to me like the cache is successfully restored on subsequent runs, but things might be confusing because I only re-ran one macOS runner each time ¹. GitHub shows the jobs from attempt 1 in attempt 2 if they were not re-run.

These look the expected behavior to me. All the runners happened to use image "20240204.1", which is either lucky or unlucky depending on how you look at it.

Of the three runs, I looked at the just the macos-14 jobs.

Oh, I only re-ran the macos-13 jobs because that's where we saw failures. Feel free to re-run some or all jobs.

Thanks @colesbury for the PR, and @hugovk for merging it 🌮🎉.. I'm working now to backport this PR to: 3.11, 3.12.
🐍🍒⛏🤖

Sorry, @colesbury and @hugovk, I could not cleanly backport this to 3.11 due to a conflict.
Please backport using cherry_picker on command line.

cherry_picker 4deb70590e1829081fb6d110e9dc6d060a49d95d 3.11

GH-115427 is a backport of this pull request to the 3.12 branch.

GH-115428 is a backport of this pull request to the 3.11 branch.