[Development] QtMultimedia and Musepack

[Allan Sandfeld Jensen]

On Saturday 23 August 2014, Olivier Goffart wrote:
> On Saturday 23 August 2014 15:46:46 Roland Winklmeier wrote:
> > Am 22.08.2014 14:04, schrieb Cornelius Hald:
> > >> I recently ported application from Qt4 to Qt5 and I rewrote a bit the
> > >> audioplayer in it. Now it is using QtMultimedia instead of Phonon.
> > 
> > There is an unresolved dependency issue with the combination Qt5 -
> > GStreamer:
> > Qt5 uses GStreamer on Linux, GStreamer itself uses libproxy, which again
> > interfaces with Qt4 and bombs the application.
> > Qt5 -> GStreamer -> ... -> libproxy -> Qt4.
> > 
> > https://bugs.kde.org/show_bug.cgi?id=323407.
> > 
> > I'm not sure who is in charge to fix this (if there is someone at all).
> > KDE closed the bug report, because its of course not their fault. Up to
> > now, I'm not aware of any workaround.
> 
> There is unfortunately no solution!
> 
> As a workaround, you can compile Qt5 in a namespace  (the -qtnamespace
> option in Qt's configure)

Using namespace or versioned symbols. I think something like -Wl,--default-
symver on all Qt modules and -Wl,--default-imported-symver on anything using 
Qt modules could solve such crashes in many cases. It doesn't solve all issues 
though, and versioned symbols have a bad reputation. Finally the two options 
are not support by the gold linker we now prefer on linux, which would require 
using version scripts instead. 

See https://blog.habets.se/2012/05/Shared-libraries-diamond-problem

Br
`Allan