I found the problem. Documenting here for posterity. I had a file in /etc/apt/preferences.d/ containing this:
Package: * Pin: Release v=18.04, -l=Ubuntu Pin-Priority: 10 I had added this a while ago to upgrade smartmontools to the version from Bionic, but forgot about it. Removing this (commenting out these 3 lines) made the do-release-upgrade succeed. ** Changed in: ubuntu-release-upgrader (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1922401 Title: do-release-upgrade fails because it marks e2fsprogs for removal To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1922401/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs