Repository navigation
Intermittent test failure in test_subprocess.test_signals #851
Description
It looks like #849 failed to automerge because of an intermittent failure in test_subprocess.test_signals: https://ci.cryptography.io/blue/organizations/jenkins/python-trio%2Ftrio/detail/PR-849/1/pipeline
The traceback is:
_________________________________ test_signals _________________________________
async def test_signals():
async def test_one_signal(send_it, signum):
with move_on_after(1.0) as scope:
async with subprocess.Process(SLEEP(3600)) as proc:
send_it(proc)
assert not scope.cancelled_caught
if posix:
assert proc.returncode == -signum
else:
assert proc.returncode != 0
await test_one_signal(subprocess.Process.kill, SIGKILL)
> await test_one_signal(subprocess.Process.terminate, SIGTERM)
../.venv/lib/python3.5/site-packages/trio/tests/test_subprocess.py:240:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
send_it = <function Process.terminate at 0x102bc6d90>
signum = <Signals.SIGTERM: 15>
async def test_one_signal(send_it, signum):
with move_on_after(1.0) as scope:
async with subprocess.Process(SLEEP(3600)) as proc:
send_it(proc)
assert not scope.cancelled_caught
if posix:
> assert proc.returncode == -signum
E assert -9 == -<Signals.SIGTERM: 15>
E + where -9 = <trio._subprocess.Process object at 0x105d6c908>.returncode
../.venv/lib/python3.5/site-packages/trio/tests/test_subprocess.py:235: AssertionError
CC: @oremanj
Activity
njsmith commentedon Jan 11, 2019
(This failure is in jenkins which we're phasing out, and indeed I have no idea why it's even running here. But I assume that if it failed here it can probably fail on other systems too.)
oremanj commentedon Jan 14, 2019
I'm thoroughly confused at this one -- we're calling
Popen.terminate()which should always send SIGTERM, we're waiting for the process to exit after sending the signal, the cancel scope wasn't cancelled so we wouldn't have sent kill()...I can nerf the test so that it permits exited-on-SIGKILL in response to sending SIGTERM, but I'm a little reluctant to do that unless we see this failure more than once - thoughts?
njsmith commentedon Jan 15, 2019
Thanks for taking a look! It seems pretty mysterious to me too.
I guess we have two goals here:
Right now we've only seen the failure once, so it's probably pretty rare, and it's not really interfering with other development. And if we nerf the test, then we won't notice future examples (if any), which will make it harder for us to understand what's going on.
So I'd leave the test alone for now, and if you don't understand it either then we can leave this open for a while and see if it happens again...
njsmith commentedon Jan 17, 2019
Here's another example, also on Jenkins macOS, same python version (3.5), exact same error: https://ci.cryptography.io/blue/organizations/jenkins/python-trio%2Ftrio/detail/PR-805/17/pipeline
oremanj commentedon May 2, 2019
We're not using Jenkins anymore, and I don't think this has shown up elsewhere. OK to close?
njsmith commentedon May 2, 2019
It seems very unlikely to me that Jenkins was actually the culprit, as opposed to some weird macOS thing. But since it isn't causing problems and we can't even prove the bug exists, I guess we can close it. (And re-open if it ever resurfaces.)
pquentin commentedon Jan 31, 2020
Seen again on Linux Python 3.6 in Azure Pipelines: https://dev.azure.com/python-trio/trio/_build/results?buildId=1461&view=logs&jobId=9a864fd9-6c8f-52ca-79ce-2aa6dca1a1de&j=9a864fd9-6c8f-52ca-79ce-2aa6dca1a1de&t=14435553-4bd6-5ab0-e7af-caf830f382a2
njsmith commentedon Jan 31, 2020
@pquentin I think that's actually another variant of #851, so I reposted over there.
pquentin commentedon Jan 31, 2020
Thanks 👍 I think you meant #1170
njsmith commentedon Jan 31, 2020
Uh... right :-)
tjstum commentedon Dec 3, 2021
I mentioned this in gitter, but I am reliably seeing this on my own macOS laptop. Happy to help with the triage or the fix but super receptive to hints!