Precompiling QML code makes ktouch hard-depend on the Qt version it is compiled with, forcing it to be rebuilt with every new Qt version. This creates an additional burden for packagers in exchange for a negligible performance gain the first time the application is run (for every subsequent run the QML code is already compiled in the cache anyway)

Built with and old Qt version and -DCOMPILE_QML=OFF, it runs fine with current Qt.