emerging kdelibs fails at the beginning because of strigi.
Created attachment 184563 [details] emerge --info
Created attachment 184565 [details] build.log
I've just installed all the qt-4.5.0 packages and strigi is Installed versions: 0.6.4(10:23:09 03/10/09)(clucene dbus exif fam hyperestraier inotify qt4 -debug -log -test)
What version of strigi do you have installed?
Was strigi 0.6.4, but I've just realized that it was a problem on my side due to having created in the past some logical links from strigi plugins in /usr/lib64/strigi to /usr/kde/4.2/lib64/strigi. Sorry for the invalid bug report...