I found the following that may help people that arrived here at this "bug":
https://wiki.ubuntu.com/PrecisePangolin/ReleaseNotes/UbuntuDesktop#Upgrading_from_Ubuntu_10.04_LTS_to_Ubuntu_12.04_LTS This, however, immediately triggers the following questions: Starting from 10.04, will "update-manager -d" install the same thing as a fresh install of 12.04? Will the system then be on a devel release branch? Or will it stay on the stable release branch? Do such things exist? How to switch between them? What's the difference between "update-manager -d" and "do-release- upgrade -d"? n.b. Sad that Ubuntu needs fine print, too. Proven, practical, precise -- and pointless for the 10.04 folks. ;-) !? ** Changed in: update-manager (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/989018 Title: Update Manager does not offer 10.04 -> 12.04 upgrade To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/989018/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
