Comment 4 for bug 46758

I attempted to reproduce this. Turns out it is not so easy, with stuff moved from archive.ubuntu.com to old-releases.ubuntu.com, and update-manager telling me at every turn to upgrade to a newer release without giving me the opportunity to do so.

From what I can read from the current source code, update-manager doesn't upgrade the system to current pacakges in the current release before dist-upgrading. I'm not sure it should: while doing so is often sensible, sometimes it requires upgrading things like the kernel, which result in a need to reboot, and all this makes the dist-upgrade experience less smooth.

Do we really need to push users to upgrade before dist-upgrading? Are there frequent problems if they don't do that?

We already push people to upgrade pretty frequently, so most people, most of the time, should have nothing to upgrade to, anyway. And the rest probably don't want to.