Upgrading from Qt 4.4 to 4.5 causes some/many/all? Qt applications to hang, in my examples within a matter of minutes when in use. This affects at least Konversation 1.2 (alpha3) and Psi 0.12.1. Re-emerging both packages fixed the hanging. I don't think revdep-rebuild picks this break up, so I am uncertain how to ascertain the state of the rest of my apps.
That's the way it is. That's why we add an ewarn message. "After a rebuild or upgrade of Qt, it can happen that Qt plugins (such as Qt" "and KDE styles and widgets) can no longer be loaded. In this situation you" "should recompile the packages providing these plugins. Also, make sure you" "compile the Qt packages, and the packages that depend on it, with the same" "GCC version and the same USE flag settings (especially the debug flag)." "Packages that typically need to be recompiled are kdelibs from KDE4, any" "additional KDE4/Qt4 styles, qscintilla and PyQt4. Before filing a bug report," "make sure all your Qt4 packages are up-to-date and built with the same" "configuration." "For more information, see http://doc.trolltech.com/4.5/plugins-howto.html"
That is an unrelated problem. Neither Konversation nor Psi are plugins.