Thanks for your detailed analysis. There is a open bug against synaptic that it is not very good about dealing with downgrades (bug #15019).
To deal with your problem you may try to remove the unoffical compiz sources.list entry (or comment it out). Then run apt-get update (it is fine if the system is still dapper and has dapper sources.list entries) to make sure that your system knows about the available packages. Then: $ sudo dpkg -r --force-depends libgl1-mesa libgl1-dev libgl1-dri libglu1-mesa libglu1-mesa-dev mesa-common-dev mesa-utils $ sudo apt-get install -f Usually it is not a good idea to use --force-depends. The apt-get install -f should be able to cleanup the damage, but there is a chance that it screws your system. So be careful and have backups of your data :) Cheers, Michael -- Can't calculate the upgrade with unofficial mesa/compiz packages https://launchpad.net/bugs/58424 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
