In (my) default setup on Fedora 23 having both qt-3.3.8qt-3.3.8 and qt-4.8.5 Environmentqt-4.8.5 environments it was also necessary to add the /usr/libxx/qt4/bin//usr/libxx/qt4/bin/ directory (temporary) totemporarily to the $PATHPATH to makeallow the cmakecmake/qmakeqmake packages findingto find the right version. This was necessary when building the code, not when running the finished QT4 app.
For
For some reason the qt3QT3 path already was installed there permanently and unfortunately at the start of the PATHPATH, which disables the possibility forprevented the QT version selector to workworking properly.