anchor.diff:  
   
     # A bootable VirtualBox virtual appliance as an OVA file (i.e. packaged OVF).
  -  ova = forAllSystems (system:
  +  ova = genAttrs [ "x86_64-linux" ] (system:
   
       with import nixpkgs { inherit system; };
   
  
positive.code: 
    # A variant with a more recent (but possibly less stable) kernel
    # that might support more hardware.
    iso_minimal_new_kernel = forAllSystems (system: makeIso {
      module = ./modules/installer/cd-dvd/installation-cd-minimal-new-kernel.nix;
      type = "minimal-new-kernel";
      inherit system;
  
negative.code:     inherit system;
    });
  
    iso_graphical = genAttrs [ "x86_64-linux" ] (system: makeIso {
      module = ./modules/installer/cd-dvd/installation-cd-graphical-kde.nix;
      type = "graphical";
      inherit system;
  