I had same problem, replaced sources.list with suggested one (xenial instead of bionic) but still unable to upgrade
Reading cache Checking package manager Reading package lists... Done Building dependency tree Reading state information... Done Hit http://security.ubuntu.com/ubuntu xenial-security InRelease Hit http://us.archive.ubuntu.com/ubuntu xenial InRelease Hit http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease Hit http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease Fetched 0 B in 0s (0 B/s) Reading package lists... Done Building dependency tree Reading state information... Done Restoring original system state Aborting Reading package lists... Done Building dependency tree Reading state information... Done === Command detached from window (Fri Jan 25 15:26:39 2019) === === Command terminated with exit status 1 (Fri Jan 25 15:26:49 2019) === -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1787712 Title: 16.04 to 18.04 do-release-upgrade fails with "Command terminated with exit status 1" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1787712/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
