Bug#935792: libglx-mesa0: error creating symbolic link (missing dependency?)

[Sven Joachim <svenjoac@gmx.de>]

Control: severity -1 normal
Control: tags -1 unreproducible moreinfo

On 2019-08-26 11:10 +0200, P.H. wrote:

> Package: libglx-mesa0
> Version: 18.3.6-2
> Severity: serious
> Justification: Policy 3.5
>
> Dear Maintainer,
>
> the update from Stretch to Buster failed with
>
>    Unpacking libglx-mesa0:amd64 (18.3.6-2) ...
>    dpkg: error processing archive /var/cache/apt/archives/libglx-mesa0_18.3.6-2_amd64.deb (--unpack):
>     error creating symbolic link './usr/lib/x86_64-linux-gnu/libGLX_indirect.so.0': No such file or directory

That's rather strange, but the diversions below show how it could
happen.

> $ env LANG=C dpkg -S /usr/lib/x86_64-linux-gnu/libGLX_indirect.so.0
> diversion by glx-diversions from: /usr/lib/x86_64-linux-gnu/libGLX_indirect.so.0
> diversion by glx-diversions to: /usr/lib/mesa-diverted/x86_64-linux-gnu/libGLX_indirect.so.0
>
> and after installing the 'glx-diversions' package, 'libglx-mesa0' is happy again.

The question is in what state the glx-diversions was before that.
Apparently it was installed due to the reported diversion, but maybe it
was broken.  In particular, apparently there was no
/usr/lib/mesa-diverted/x86_64-linux-gnu directory, that's why dpkg
failed to create the symlink there.  However, that directory is shipped
in the glx-diversions package.

> I am not sure what exactly happened, as my other computers upgraded
> smoothly and while they do have 'libglx-mesa0' installed, they do not
> need the 'glx-diversions' package. I guess the different graphic card
> drivers are to thank for...
>
>
> Anyway, this might only happen in strange environments but since my
> system seems sound, it is definitely a problem.

I don't think your system had been sound when you encountered the
unpacking error.  Installing/upgrading glx-diversions appears to have
fixed it, though.

I tried to reproduce your problem by installing glx-diversions from
stretch in a chroot, then installing libglx-mesa0 from buster.  This
worked just fine, so unless you can give additional information, there's
not much we can do.

Cheers,
       Sven