Description of problem:
Marble has seen some upstream updates since version 15.08 has been released.
Version-Release number of selected component (if applicable):
should be: 16.12
always – packaging
https://cgit.kde.org/marble.git and http://download.kde.org/stable/applications/16.12.0/src/
marble-widget is the old kde4-based version, yes.
pulls in more recent qt5/kf5-based versions, latest packaged for f25 is currently 16.08.3
(probably will wait for 16.12.1 before doing updates again).