Testing not having all your updates installed.
bdmurray@clean-bionic-amd64:/tmp$ apt-cache policy ubuntu-release-upgrader-core ubuntu-release-upgrader-core: Installed: 1:18.04.27 Candidate: 1:18.04.27
bdmurray@clean-bionic-amd64:/tmp$ do-release-upgrade -d Checking for a new Ubuntu release Please install all available updates for your release before upgrading.
So that bit passed the verification test.
Testing not having all your updates installed.
bdmurray@ clean-bionic- amd64:/ tmp$ apt-cache policy ubuntu- release- upgrader- core release- upgrader- core:
ubuntu-
Installed: 1:18.04.27
Candidate: 1:18.04.27
bdmurray@ clean-bionic- amd64:/ tmp$ do-release-upgrade -d
Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.
So that bit passed the verification test.