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machines appear to have pseudo-TTY issues

See original GitHub issue

Describe the bug

A Go test that makes use of pseudo-TTYs works fine on both Linux and Mac locally, and on Linux on Actions. However, on Mac on Actions, it fails pretty regularly, about a quarter of the time.

To Reproduce

Install Go 1.14.x
Clone https://github.com/mvdan/sh
Revert https://github.com/mvdan/sh/commit/ab43dfa8ae84bf3e4c10176a4bd4d837aa97ba9a to re-enable the flaky test
Run the test a bunch of times, via go test -run TestRunnerTerminalExec/Pseudo ./interp

You can hammer the test much harder by using stress. For example, to run 64 parallel processes until you hit a failure:

go test -vet=off -c -o test && stress -p=64 ./test -test.run TestRunnerTerminalExec/Pseudo

Expected behavior

No failures, ever. @theclapp was nice enough to run the stress line above, and he got zero failures even after 200k runs in over fifteen minutes. Likewise, I can’t reprodue any issue on Linux.

Runner Version and Platform

From a recent failed job on macos-latest today, Current runner version: '2.165.2'. Links below.

What’s not working?

The test fails with a weird signal: hangup error:

--- FAIL: TestRunnerTerminalExec (0.00s)
    --- FAIL: TestRunnerTerminalExec/Pseudo (0.04s)
##[error]        terminal_test.go:129: signal: hangup
FAIL
FAIL	mvdan.cc/sh/v3/interp	3.529s

Below is a list of such failures in the past few weeks:

I really don’t know what else to try. Given that physical Mac machines of ours can’t reproduce the issue, and that the error seems to come from a OS signal, I don’t know how else to proceed but to raise a bug here.

/cc @myitcv @leitzler

Issue Analytics

State:
Created 3 years ago
Reactions:3
Comments:15 (4 by maintainers)

Top GitHub Comments

1reaction

myitcvcommented, Mar 27, 2020

We’re also seeing issues with the Mac builders for the https://github.com/govim/govim project, to the extent that we had to disable the Mac tests:

https://github.com/govim/govim/commit/2d6e2fb03301c6c5f512f18b17aa0a5b00a9d575

Our tests are considerably more involved than @mvdan’s so I suspect using the repro above will be simpler. But in case you need the repro steps, the linked commit gives the steps our mac builds used to follow before we disabled them.

Very happy to provide more info/help diagnose - we’re just out of ideas on our side 😃

0reactions

nikola-jokiccommented, Mar 1, 2022

@mvdan, thank you for notifying us!