It's just possible that this is caused by libwacom2 being the best part of 2 years outdated w.r.t. GNOME https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=781103
-- Andrew Chadwick -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org