anchor.diff:    localDefs = with builderDefs; builderDefs.passthru.function rec {
       src = "";/* put a fetchurl here */
   
  -    buildInputs = [mkfontdir mkfontscale ttmkfdir];
  +    buildInputs = [mkfontdir mkfontscale];
       configureFlags = [];
       inherit fontDirs;
       installPhase = fullDepEntry ("
  
positive.code:     rm fonts.alias
      mkfontdir
      mkfontscale
      mv fonts.scale fonts.scale.old
      mv fonts.dir fonts.dir.old
      ttmkfdir
      cat fonts.scale.old >> fonts.scale
      cat fonts.dir.old >> fonts.dir
      rm fonts.dir.old
      rm fonts.scale.old
      cat \$( find ${fontalias}/ -name fonts.alias) >fonts.alias
    ") ["minInit" "addInputs"];
    };
  
negative.code: 
  ###### implementation
  let
    inherit (pkgs) builderDefs;
    inherit (pkgs.xorg) mkfontdir mkfontscale fontalias;
  
    fontDirs = config.fonts.fonts;
  