Buster is on kajongg 16.08, tomorrow KDE 17.12 will be tagged. Please consider updating. The depencendy of python-kde4 has gone. 17.12 is ported to python3, python2 is not supported anymore. 17.12 is ported to qt5, qt4 is not supported anymore. New dependency is twisted 16.6.0 but Buster already has 17.9.0 17.12 comes with a lot of cleanups, removing many bugs, especially about unicode.