/usr/local/lib/lipopt.so.0 is not a supported Ubuntu library. I imagine this is the cause of your issues. I'd suggest that you remove this file and try the operation again.
** Changed in: mysql-5.5 (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to mysql-5.5 in Ubuntu. https://bugs.launchpad.net/bugs/1035919 Title: package mysql-server-5.5 5.5.24-0ubuntu0.12.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 255 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mysql-5.5/+bug/1035919/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs