Re: Help needed updating vlc to version 3.0.1.

[Roel Janssen <roel@gnu.org>]

Roel Janssen <roel@gnu.org> writes:

> Mark H Weaver <mhw@netris.org> writes:
>
>> Hello Guix,
>>
>> Below I've attached a draft patch to update vlc to 3.0.1, and also to
>> add several more inputs based on reading the output of the 'configure'
>> script.
>>
>> It builds successfully and mostly works except for one problem: the
>> icons are missing from the control buttons on the main window of the Qt
>> interface.  The icons in question are .svg files in the source tarball,
>> but are converted into data structures within C++ source code using
>> 'rcc'.
>>
>> strace reveals that vlc is performing 'stat' system calls on bogus file
>> names beginning with ":/", e.g. ":/toolbar/play_b.svg".  These
>> correspond to the missing icons.  According to
>> <https://doc.qt.io/archives/qt-4.8/resources.html>, these names that
>> begin with ":/" are meant to be references to resources that were
>> imported using 'rcc'.
>>
>> I can't afford to spend more time on this right now.  I don't use vlc
>> myself, but for security reasons I think it's important to keep our
>> media players up-to-date, especially media players like vlc that bundle
>> their own codecs.  I expect that vlc is quite popular, which makes it
>> all the more important.
>>
>> I'm hoping that someone with more knowledge of Qt will step up to debug
>> this problem.  Any volunteers?
>>
>> Note, this patch is based on core-updates, but hopefully it would work
>> on 'master' too.
>
> Thanks a lot for working on this!  I applied your patch to ‘master’ and
> built VLC.  It is missing the icons.
>
> Then I manually built it inside a ‘guix environment vlc’.
> Launching it shows the icons.  Leaving the environment and running the
> same executable misses the icons.
>
> Could it be that we need to propagate an input?
> I'll try to dissect it further.

After setting QT_PLUGIN_PATH outside of the environment, the icons
appear in the Guix-compiled vlc-3.0.1.  I think the files in
QT_PLUGIN_PATH do not originate from VLC, but instead from Qt and
QtSvg.

Should we wrap the executable so that QT_PLUGIN_PATH is defined?

Thanks!

Kind regards,
Roel Janssen