I tried recreating this and while the system did not reboot sources.list was not restored to bionic.
bdmurray@clean-bionic-amd64:~$ tail /var/log/dist-upgrade/screenlog.0 System upgrade is complete. Restart required To finish the upgrade, a restart is required. If you select 'y' the system will be restarted. Continue [yN] y === Command terminated normally (Mon Aug 3 18:44:27 2020) === bdmurray@clean-bionic-amd64:~$ cat /etc/apt/sources.list deb http://192.168.10.7/ubuntu focal main restricted universe multiverse deb http://192.168.10.7/ubuntu focal-updates main restricted universe multiverse # deb http://archive.ubuntu.com/ubuntu bionic-proposed main restricted universe multiverse deb http://192.168.10.7/ubuntu focal-security main restricted universe multiverse deb-src http://192.168.10.7/ubuntu focal main restricted universe multiverse deb-src http://192.168.10.7/ubuntu focal-updates main restricted universe multiverse # deb-src http://archive.ubuntu.com/ubuntu bionic-proposed main restricted universe multiverse deb-src http://192.168.10.7/ubuntu focal-security main restricted universe multiverse bdmurray@clean-bionic-amd64:~$ ls -lh /sbin/reboot lrwxrwxrwx 1 root root 28 Jul 9 2019 /sbin/reboot -> /lib/molly-guard/molly-guard -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1888916 Title: upgrade from bionic to focal a server with molly-guard moves back sources.list to bionic entries To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1888916/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
