Qt5 has several changes that break the API-compatibility to Qt4. Especially the transition to the Lighthouse/QPA architecture makes it necessary to adjust KWin accordingly.
|Status||Description||affected parts of KWin|
|TODO||QRegion::handle() does not return a X11 Region any longer||client.cpp|
|TODO||QPixmap::handle() does not return a X11 Pixmap any longer||decoration painting, tfp|