I tried to upgrade from 10.04 to 10.10 - now that Ubuntu 10.10 is finally released. I used update-manager -d and the first window after pressing the upgrade button says that it is still a development release.
Is this true? Or have they not changed this window yet?
update-manager -d is the command to upgrade to development trunk versions of Ubuntu.
However, I think I recall Ubuntu updates the repositories to notify about the new release a few days after the release is live so that when people are prompted to upgrade, the bandwidth use spike from the day 1 enthusiasts has been fully absorbed. By using that route, you should still end up with a copy of "blessed" Ubuntu 10.10.
That said, even if it was marked as a development version, it wouldn't be any different. Go ahead, make your day!
You just have to run the update manager as normal from the System -> Admin menu as normal, and you'll get an option at the top of the windows to upgrade your distro.
When you type lsb_release -a in your terminal, you'll see that it says Ubuntu 10.10. Before there was also 'development brach' added.
