Configuring a network (but not letting the apt mirror connect) crashes the installer

[Ethan Myers]

If your network configuration does not pass subiquity's ubuntu archive mirror check, the installation can continue, but mostly fails. I think the install should instead proceed as if there is no network, which works fine and is a smoother experience.

To subiquity's credit, users are warned: "The check of the mirror URL failed. You can continue but it is very likely that the installation will fail".

Instead of letting the installation continue and the install fail, is it possible to proceed as if there is no network connection? Not entering a network config allows for a flawless installation, but allowing users to proceed with a likely broken install does not seem to be the right approach.

In my case, the mirror is actually accessible, but an unreachable NTP server results in package updates that are not valid yet.