[Qt-creator] Custom widget not showing in Qt Designer on Linux

[Friedemann Kleint]

Hi Rob,

> Originally Creator was saying it couldn't find Qt Designer, so I
> installed it [designer] from my (Mandriva) repositories and that works
> fine other than with the customer widget. So, I wondered whether it was
> this issue with different builds.

Yes, it means the installed version of Qt Designer is older than the one from 
the SDK and cannot load the plugins compiled by the SDK.

> 
> With 2010.02 sdk installed, once again, I cannot launch designer from
> creator. (By right clicking on the .ui file in the project explorer.) If
> I reinstall designer from my repositories I guess I will be able to.
> Creator just tells me:
> 
> 'The application "Qt Designer" could not be found'.
> If I try and launch designer from the command line I get this error:
> 
> makekdewidgets(12371)/kdecore (KSycoca) KSycocaPrivate::openDatabase:
> Trying to open ksycoca from  "/var/tmp/kdecache-robertw/ksycoca4"
> designer: symbol lookup error:
> /usr/lib/kde4/plugins/phonon_backend/phonon_gstreamer.so: undefined
> symbol: _ZN6Phonon12PulseSupport11getInstanceEv
> 
> Is there something I am missing here or is designer broken on Linux with
> 2010.02?

This probably originates from Qt Designer trying to load a phonon plugin. Try 
to remove /opt/qtsdk-2010.02/qt/plugins/designer/libphononwidgets.so and clear 
the environment variable QT_PLUGIN_PATH.  If it still doesn't work, try to put  
/opt/qtsdk-2010.02/qt/bin as the first directory in the PATH. 

Regards,
Friedemann
-- 
Friedemann Kleint
Nokia, Qt Development Frameworks