An early announcement was made that Qt4 is going to be removed from Stretch, otherwise known as Jessie + 1. pumpa is currently based on Qt4. While it is not necessary or appropriate to break Jessie's current freeze to switch to Qt5 it is necessary to begin re-factoring code to prepare for this coming switch. The full early announcement can be read at http://perezmeyer.blogspot.com/2014/11/early-announce-qt4-removal-in-jessie1.html