You have python3.8 packages installed from the "deadsnakes" PPA which is preventing the upgrade from being calculated. You'll want to remove those packages and then the upgrade may be calculable.
** Tags added: third-party-packages ** 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/1876088 Title: Unable to upgrade to ubuntu 20.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1876088/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs