The issue seems to be /etc/apt/sources.list.d/prequists-sources.list which in it has:
# sources.list fragment for pre-requists (mirror from sources.list + fallback) # this is safe to remove after the upgrade deb http://ubuntu.osuosl.org/ubuntu/ precise-updates main # when this changes from -proposed to -updates, ensure to update # DistUpgradeController.py:1393 as well deb http://archive.ubuntu.com/ubuntu/ precise-updates main ** Changed in: update-manager (Ubuntu) Status: New => Triaged ** Changed in: update-manager (Ubuntu) Importance: Undecided => Medium -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/959700 Title: duplicate sources.list entry after upgrade lucid2precise To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/959700/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
