The problem was the libpython packages you installed with the blender PPA that you had enabled.
libpython3.4 3.4.0-2ubuntu1irie1~saucy1 0 libpython3.4-minimal 3.4.0-2ubuntu1irie1~saucy1 1 libpython3.4-stdlib 3.4.0-2ubuntu1irie1~saucy1 1 Those version numbers are greater than the version in Trusty and subsequently block the upgrade to it. $ rmadison libpython3.4 libpython3.4 | 3.4.0-2ubuntu1 | trusty | amd64, arm64, armhf, i386, powerpc, ppc64el libpython3.4 | 3.4.1-10 | ubuntu-rtm/14.09 | amd64, armhf, i386 libpython3.4 | 3.4.1-10ubuntu1 | utopic | amd64, arm64, armhf, i386, powerpc, ppc64el ** Changed in: ubuntu-release-upgrader (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1363847 Title: Update failure from 13.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1363847/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs