I've encountered the same issue. It seems it's related to "a collision with some other GEM." There is already a solution to this issue on Debian side e.g https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=899067
I've been able to solve the issue by applying the provided patch manually from the issue (did not try applying the diff automatically). ** Bug watch added: Debian Bug tracker #899067 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=899067 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1835966 Title: Screenruler doesn't start (Lubuntu 18.04.2) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/screenruler/+bug/1835966/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
