Attached the dist-upgrade apt.log that confirms that the issue seems to be around the tk package
** Attachment added: "/var/log/dist-upgrade/apt.log" https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1286288/+attachment/4001058/+files/log.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1286288 Title: Calculation of upgrade failed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1286288/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
