On further investigation, this appears to be related to the gnome default applications tool. It seems to have decided that I had a custom default.
** Also affects: gnome-control-center (Ubuntu) Importance: Undecided Status: New -- Cannot run custom launcher https://bugs.launchpad.net/bugs/134779 You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is a bug contact for gnome-control-center in ubuntu. -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs