[PyQt] designer segfaults on startup after installing libpythonplugin.so and custom widget

[Glen W. Mabey]

On Tue, Feb 05, 2008 at 09:22:37AM -0600, Glen W. Mabey wrote:
> On Tue, Feb 05, 2008 at 02:01:50AM -0600, Phil Thompson wrote:
> > On Monday 04 February 2008, Glen W. Mabey wrote:
> > > Nope.  I run
> > >
> > >     /usr/local/bin/python2.5 plugins.py
> > >
> > > from the examples/designer/plugins directory which first pops up that
> > > info window and then launches designer, but I neither see the PyQt Examples
> > > group nor anything new in the toolbox.  Help -> About Plugins says that
> > > it couldn't find any.
> > 
> > Any at all, or any of the PyQt examples?
> 
> None at all.  Which should have raised a flag for me because I didn't
> see any of the Qt3 support items which enter as plugins, if I understand
> it correctly.
> 
> > Obviously the problem is with the PyQt build itself, rather than your
> > particular plugin. Did you do anything "non-standard"?
> 
> Actually, yes.  I spent most of the day yesterday working to get things
> better situated and more correctly installed.

The installation scheme I'm using is to install each package so that all
its files reside in

  /usr/local/stow/Python-2.5.1
  /usr/local/stow/qt4-4.3.3
  /usr/local/stow/sip-4.7.3-py2.5
  /usr/local/stow/pyqt4-4.3.3-py2.5  
  /usr/local/stow/qscintilla2-2.1  

and then running the 'stow' utility to create symlinks from
/usr/local/bin/ into (for example) /usr/local/stow/qt4-4.3.3/bin/ thus 
placing executables and libraries into standard system directories.

So, with just Python, qt4, and sip in a "stowed" state, when I launch
designer it shows the Qt3 support items in the toolbox.  As soon as I
stow pyqt4, those Qt3 support items no longer appear.

Just a sampling of the contents of those directories:

  /usr/local/stow/qt4-4.3.3/plugins/designer/libcustomwidgetplugin.so
  /usr/local/stow/qt4-4.3.3/plugins/designer/libcustomwidgetplugin.so.debug
  /usr/local/stow/qt4-4.3.3/plugins/designer/libpythonplugin.so
  /usr/local/stow/qt4-4.3.3/plugins/designer/libqt3supportwidgets.so
  /usr/local/stow/qt4-4.3.3/plugins/designer/libqt3supportwidgets.so.debug
  /usr/local/stow/qt4-4.3.3/plugins/designer/libtaskmenuextension.so

  /usr/local/stow/pyqt4-4.3.3-py2.5/plugins/designer/libpythonplugin.so
  /usr/local/stow/pyqt4-4.3.3-py2.5/plugins/designer/python/

  /usr/local/stow/qscintilla2-2.1/plugins/designer/libqscintillaplugin.so

Thus, when each package gets stowed, appropriate symlinks are found in

  /usr/local/plugins/designer/

So, it seems to me that the compile options and install layout that I
have chosen cause libpythonplugin.so to make the whole designer plugin
system to bomb.

Glen