checking for qmake-qt5... no checking for qmake... /usr/lib64/qt5/bin/../bin/qmake checking for qmake... (cached) /usr/lib64/qt5/bin/../bin/qmake checking for Qt library version >= 5.1... no; Qt 5.1 or greater is required Looks like another addition to bug 589412.
Fixed by media-sound/qsynth-0.4.2-r1.