-s, --script: never prompts for user intervention
Sometimes the NixOS installer tests fail when they invoke parted, e.g.
https://hydra.nixos.org/build/62513826/nixlog/1. But instead of exiting
right there, the tests hang until the Nix builder times out (and kills
the build). With this change the tests would instead fail immediately,
which is preferred.
While at it, use "parted --script" treewide, so nobody gets build
timeout due to parted error (or misuse). (Only nixos/ use it, and only
non-interactive.)
A few instances already use the short option "-s", convert them to long
option "--short".
Systemd upstream provides targets for networking. This also includes a target network-online.target.
In this PR I remove / replace most occurrences since some of them were even wrong and could delay startup.
Setting nixosVersion to something custom is useful for meaningful GRUB
menus and /nix/store paths, but actuallly changing it rebulids the
whole system path (because of `nixos-version` script and manual
pages). Also, changing it is not a particularly good idea because you
can then be differentitated from other NixOS users by a lot of
programs that read /etc/os-release.
This patch introduces an alternative option that does all you want
from nixosVersion, but rebuilds only the very top system level and
/etc while using your label in the names of system /nix/store paths,
GRUB and other boot loaders' menus, getty greetings and so on.
