When it comes to qtbase-opensource-src at least, I don't think there's anything left to fix at this time regarding the problem, with the latest 5.0.2 work in 13.10 synced with Debian. The configuration placement changes in there together with newer qtchooser should help upstream to revert the PATH forcing, although a resync with Debian's Qt4 would also be needed still to have automatic fallback to Qt4.
This comes from KDE upstream (http:// quickgit. kde.org/ ?p=kde- workspace. git&a=blob& h=fde85473019d3 7a50d3d233dc45a d96ee76359d8& hb=07d3ac9d8c78 1755d19c71ccde6 d182868a2bfb5& f=startkde. cmake#l19) which has forced PATH to have qt4 path as the first item, regardless of qtchooser, qt5-default and so on. It's obviously a workaround (for KDE's Qt4 qdbus usage) that should hopefully go away. You can use a different PATH when in an own terminal window so that qtchooser can do its job.
When it comes to qtbase- opensource- src at least, I don't think there's anything left to fix at this time regarding the problem, with the latest 5.0.2 work in 13.10 synced with Debian. The configuration placement changes in there together with newer qtchooser should help upstream to revert the PATH forcing, although a resync with Debian's Qt4 would also be needed still to have automatic fallback to Qt4.