Maybe you should be more curious about unknown tweak: 'script' is a generic word for a suite of codes; and ppa-purge refer indeed to each installed ppa.
https://askubuntu.com/questions/307/how-can-ppas-be-removed ** Changed in: ubuntu-release-upgrader (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1769576 Title: not able to upgrade from ubuntu 16.04 to 18 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1769576/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
