I believe this is a bug in screen. The postinst script has code to handle the changed requirements for /run/screen permissions, but then immediately afterwards a debhelper code snippet runs which clobbers them again.
** Package changed: ubuntu-release-upgrader (Ubuntu) => screen (Ubuntu) ** Changed in: screen (Ubuntu) Importance: Undecided => High ** Changed in: screen (Ubuntu) Status: New => Triaged -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1761997 Title: /var/run needs mode 777 in bionic To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/screen/+bug/1761997/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs