CI is failing on current main: test_asyncio.test_taskgroups

[Eclips4]

Bug report

Bug description:

Example of failing CI:

• https://github.com/python/cpython/actions/runs/11331846505/job/31512771372?pr=125471
• https://github.com/python/cpython/actions/runs/11331026920/job/31510134859?pr=125469
• https://github.com/python/cpython/actions/runs/11331846505/job/31512771372?pr=125471

CPython versions tested on:

CPython main branch

Operating systems tested on:

No response

Linked PRs

• gh-125472: Revert "gh-124958: fix asyncio.TaskGroup and _PyFuture refcycles (#12… #125476
• [3.13] gh-125472: Revert "gh-124958: fix asyncio.TaskGroup and _PyFuture refcycles (GH-12… (GH-125476) #125478
• gh-124958: Revert "gh-125472: Revert "gh-124958: fix asyncio.TaskGroup and _PyFuture refcycles ... #125486

[Eclips4]

Perhaps the bad commit is the d5dbbf4

[picnixz]

cc @graingert

[1st1]

Yeah, OK to revert. Weird that it did pass the GH CI.

[zware]

Expectation is that it conflicts with a more recent change to main; the PR 124959 branch was not fully up to date before merge.

[terryjreedy]

We allow PRs to be merged (if merge-compatible) with a passing GH CI for an older version of main because A) requiring a fresh green CI for every code change would drastically slow down progress and b) we have buildbots retesting all recent merges together. A coredev considering merging a PR with an 'old' green CI can trigger a retest by updating the patch, which is now easy right on the PR, and set automerge upon success.