You've installed python3 packages from a PPA which is preventing the upgrade, as the package versions are greater than those in Trusty, to 14.04.
libpython3.4 3.4.0-2ubuntu1irie1~precise1 1 libpython3.4-minimal 3.4.0-2ubuntu1irie1~precise1 1 libpython3.4-stdlib 3.4.0-2ubuntu1irie1~precise1 1 ** Summary changed: - upgrade from 12.04 to 14.04 not possible + upgrade from 12.04 to 14.04 not possible due to python3 from a PPA -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1324196 Title: upgrade from 12.04 to 14.04 not possible due to python3 from a PPA To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/1324196/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
