anchor.diff:      else "nixos-${builtins.readFile ../../VERSION}"
   , compressImage ? false
   , nixpkgs ? ../../../nixpkgs
  -, services ? ../../../services
   # This option allows easy building of Rescue CD with 
   # modified package set / driver set / anything.
   # For easier maitenance, let overrider know the current
  
positive.code:   nixosTarball = makeTarball "nixos.tar.bz2" ../..;
  
  
    # Put Services in a tarball.
    servicesTarball = makeTarball "services.tar.bz2" services;
  
  
    # Put Nixpkgs in a tarball.
    nixpkgsTarball = makeTarball "nixpkgs.tar.bz2" nixpkgs;
  
  
negative.code:               tar xjf /install/nixos.tar.bz2 -C /etc/nixos/nixos
                mkdir -p /etc/nixos/nixpkgs
                tar xjf /install/nixpkgs.tar.bz2 -C /etc/nixos/nixpkgs
                chown -R root.root /etc/nixos
              end script
            ";
  