Comment 3 for bug 1185581

My server was upgrading from 12.10 to 1304. It had byobu installed and set to run when I logged in, so when I started the do-release-upgrade it was from within the byobu session. do-release-upgrade did start its screen session, but I was unable to connect directly to that (screen -list didn't list the session but I could see it in the process list, however I can't remember if I tried as root or not) and the byobu/tmux session refused to reconnect due to a version incompatibility. I will reproduce in a VM to ensure I really couldn't get at the screen session do-release-upgrade started, but the root of the problem seems to be that I was using byobu(tmux) to launch the do-release-upgrade and there is an incompatibility between the tmux version in 12.10 and 13.04.