Bug#737054: oss-compat: deadlocks during remove

[Andreas Beckmann]

Hi Stephen,

On 2014-01-29 23:08, Stephen Kitt wrote:
>> >From the attached log (scroll to the bottom...):
>>
>> 0m19.1s DEBUG: Starting command: ['chroot', '/tmp/piupartss/tmpqN70Hj',
>> 'apt-get', 'remove', 'kmod', 'libkmod2:amd64', 'oss-compat'] 59m19.1s
>> ERROR: Terminating command due to excessive runtime 59m19.6s DUMP: 
>>   
>>   
>>   ***** Command was terminated after exceeding runtime limit (3540 s) *****
>> 59m19.6s DEBUG: Command ok: ['chroot', '/tmp/piupartss/tmpqN70Hj',
>> 'apt-get', 'remove', 'kmod', 'libkmod2:amd64', 'oss-compat'] 59m19.6s INFO:

> Why is kmod purged before oss-compat? oss-compat depends on kmod, so
> according to policy section 7.2, kmod should be left at least unpacked as
> long as oss-compat is in the "configured" state (so that postinst and prerm
> can use kmod).

There is no guarantee on purge ordering, and therefore piuparts tries
the worst case for a packages: after all its dependencies. But purge is
not your problem here, piuparts first runs remove and thereafter purge.
It is the the apt-get remove command that does not return (therefore no
output is shown in the log). And the remove order is computed by apt-get
according to the dependencies.

> (In any case there is a bug in oss-compat's prerm, I need to at least detach
> the subshells that are started to remove the modules.)

But they should terminate gracefully if the modules are not loaded or
/sys is not mounted or whatever may fail ... piuparts won't like
processes being left running after the removal of a package ...

Andreas