To close the loop here - /sbin/reboot -f did reboot the system and it came back in a perfectly working, systemd enabled system. It was definitely a broken user experience though.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1608689 Title: do-release-upgrade left machine in unrebootable state To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1608689/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
