anchor.diff:      /nix/var/nix/gcroots/per-user/hydra/hydra-roots --argstr \
       system i686-linux --argstr system x86_64-linux --arg \
       nixpkgs "{outPath = ./}" .... release.nix
  -    
  +
     Hydra can be installed with "nix-env -i hydra".
   */
   with (import ./release-lib.nix);
  
positive.code:   firefox35Pkgs = {
      firefox = prio 150 linux;
    };
    
    firefox36Pkgs = {
      firefox = linux;
    };
    
    gnome = {
      gnome_panel = linux;
      metacity = linux;
  
negative.code:     xset = linux;
    };
  
  } ))
  
  