Ah, kisak-mesa seems to have been the culprit. After sudo ppa-purge ppa:kisak/kisak-mesa the upgrade is now running.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1916959 Title: Start of LTS upgrade 18.04 to 20.04 failed/aborted To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1916959/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
