On the advice of AlbertoSalvia Novella , I've submitted a new bug report against dbus with links to all the bugs (in my install of Xubuntu 14.04) that I vaguely suspect are related to one another:
Bug #1347272 (DBus communication problems affecting multiple packages) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/976638 Title: pkexec does not find any authentication agent To manage notifications about this bug go to: https://bugs.launchpad.net/policykit-1/+bug/976638/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
