anchor.diff:      with import <nixpkgs> { inherit system; };
   
       let
  -      versionModule = { system.nixosVersionSuffix = lib.optionalString (!officialRelease) versionSuffix; };
   
         config = (import lib/eval-config.nix {
           inherit system;
  
positive.code:   pkgs = import <nixpkgs> { system = "x86_64-linux"; };
  
  
    makeIso =
      { module, type, description ? type, maintainers ? ["eelco"], system }:
  
  
negative.code:       config = (import lib/eval-config.nix {
          inherit system;
          modules =
            [ versionModule
              ./modules/virtualisation/virtualbox-image.nix
              ./modules/installer/cd-dvd/channel.nix
              ./modules/profiles/demo.nix
            ];
  