Installed using
```
> sudo nixos-install --root /tmp/new-install/ --flake .#nyx --impure --no-root-passwd
```

where `/tmp/new-install` was the moint point of the target FS.

The root user is effectively deactivated, hence the additional setup:
- users are part of the `wheel` group
- password needs to be set before first boot:
    - `nix-enter --root /tmp/new-install`
    - `passwd <username>`