Intermittent failure in mining_getblocktemplate_longpoll.py #26962

Seen on master, https://cirrus-ci.com/task/6706434163867648?logs=ci#L5577

2023-01-24T20:06:14.173000Z TestFramework (INFO): Test that introducing a new transaction into the mempool will terminate the longpoll
2023-01-24T20:07:34.182000Z TestFramework (ERROR): Assertion failed
Traceback (most recent call last):
  File "/tmp/cirrus-ci-build/ci/scratch/build/bitcoin-i686-pc-linux-gnu/test/functional/test_framework/test_framework.py", line 134, in main
    self.run_test()
  File "/tmp/cirrus-ci-build/ci/scratch/build/bitcoin-i686-pc-linux-gnu/test/functional/mining_getblocktemplate_longpoll.py", line 74, in run_test
    assert not thr.is_alive()
AssertionError
2023-01-24T20:07:

My guess is that the thread (or memory, or storage) is put to sleep for several seconds. Not sure how to fix this, though.

Doesn't look very critical to me, plus it's very rare (I've seen it just this once), so maybe close this as a one-off at some point.

I am seeing it regularly. (A few times per month, depending on how many CI runs you look at in the month, see #19684 (comment))

But there is also the tx delay issue, #19732, so maybe we just give up and accept some failures