anchor.diff:  
     website = pkgs.stdenv.mkDerivation rec {
       name = "hsluv-website";
  -    inherit nodejs nodeModules pickerJsDist;
  +    inherit nodejs pickerJsDist mustacheJs nodePackageDist;
       src = ./website;
       buildInputs = [nodejs];
       demoFavicon = genDemoImage "favicon";
  
positive.code:     sha256 = "09gx8ra0m52bm0zdfbwb151b5ngvv7bq1367pizsgmh5r4sqigzk";
    };
  
    nodeModules = pkgs.stdenv.mkDerivation rec {
      name = "node-modules";
      inherit nodejs mustacheJs nodePackageDist;
      buildInputs = [nodejs];
      builder = builtins.toFile "builder.sh" ''
        source $stdenv/setup
        HOME=.
        npm install $mustacheJs
        npm install $nodePackageDist
        mkdir $out
        cp -R node_modules/* $out
      '';
    };
  
    genDemoImage = i : pkgs.stdenv.mkDerivation rec {
      name = "hsluv-demo-${i}";
      inherit nodejs nodeModules imagemagick;
      generateImagesJs = ./website/generate-images.js;
      buildInputs = [nodejs imagemagick];
      builder = builtins.toFile "builder.sh" ''
        source $stdenv/setup
        export NODE_PATH=$nodeModules:$NODE_PATH
        node $generateImagesJs ${i} > img.pam
        mkdir $out
        convert img.pam $out/${i}.png
  
negative.code:     demoHpluvChroma = genDemoImage "hpluv-chroma";
      builder = builtins.toFile "builder.sh" ''
        source $stdenv/setup
        export NODE_PATH=$mustacheJs:$nodePackageDist:$NODE_PATH
  
        mkdir $out
        mkdir $out/images
  