installation

first, you must edit /etc/nixos/configuration.nix to include the following:

{
  config,
  pkgs,
  ...
}: {
  imports = [
    <...>
  ];

  nix.settings.experimental-features = [
    "nix-command"
    "flakes"
  ];

  <...>

  networking.hostname = "<hostname>";

  <...>

  environment.systemPackages = with pkgs; [
    git
  ];
}

then, run sudo nixos-rebuild switch once to apply those changes.

reboot, to make sure that everything applied properly.

finally, run sudo nixos-rebuild switch --flake /home/grey/nixos#<hostname> to apply the flake.

reboot again, and you should now land on your desktop/login screen!

now you have access to nh os switch ~/nixos, and shouldn't touch the global config ever again.