*** This bug is a duplicate of bug 63205 *** According to the apt-cache policy libgl1-mesa-dri output you've left in bug 63205 your bug is a duplicate of that one. The only difference is that you no longer have third-party repositories enabled in the sources.list file, though some packages remain installed in your system. Please remove libgl1-mesa and libgl1-mesa-dri from your system and try upgrading again.
** This bug has been marked a duplicate of bug 63205 Can't install 'ubuntu-desktop' -- Could not calculate upgrade https://launchpad.net/bugs/63301 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs