Bug#851870: autopkgtest-virt-qemu: Hangs if test causes a kernel panic

[Martin Pitt]

Hello Iain,

Iain Lane [2017-01-19 14:06 +0000]:
> I was attempting to debug/fix LP: #1630578, so I wrote the attached
> package to trigger a panic manually.
> 
> Seems that the qemu runner hangs when the panic happens. (Hopefully it's
> going to timeout eventually.)

It does time out:

| $ runner/autopkgtest -B /tmp/panic -d --timeout-test=60 --timeout-copy=10 -- qemu -d autopkgtest-zesty-amd64.img
| [...]
| autopkgtest [11:03:40]: test panic: [-----------------------
| [...]
| make[1]: Leaving directory '/usr/src/linux-headers-4.9.0-11-generic'
| autopkgtest [11:04:40]: ERROR: timed out on command [...]
| autopkgtest [11:04:41]: test panic: -----------------------]

it then tries to copy the results, which times out as well:

| autopkgtest-virt-qemu: DBG: executing copyup /tmp/autopkgtest.6i3fb7/panic-stdout /tmp/autopkgtest.output.e4e00v7l/panic-stdout
| autopkgtest: DBG: got reply from testbed: timeout
| autopkgtest: WARNING: Copying up test output timed out, ignoring
| autopkgtest [11:04:51]: test panic:  - - - - - - - - - - results - - - - - - - - - -
| panic                FAIL timed out

and exits with error 4 (i. e. test failure). So while this is certainly not
optimal, it is at least reasonable. So I don't think it's an urgent/critical
bug.

> I thought about solving by slightly refactoring the auxverb use to use
> asyncio when waiting for the command to exit, and then also for reading
> from ttyS0 for occurrences of 'Kernel panic'.

This should take care to not catch kernel warnings or oopses -- when these
happen, the machine should limp on normally, and package tests like kerneloops
even trigger them deliberately.

Thanks,

Martin

-- 
Martin Pitt                        | http://www.piware.de
Ubuntu Developer (www.ubuntu.com)  | Debian Developer  (www.debian.org)