anchor.diff:  rec {
  +  pkgs = import (pkgsSrc) {};
     pkgsOriginal = import <nixpkgs> {};
     pkgsSrc = pkgsOriginal.fetchzip {
  -    url = "https://github.com/NixOS/nixpkgs/archive/ebe19f5db0d9df4d86cd2012b44dd4249062d891.zip";
  -    sha256 = "0vg6snrrwgih0iwdqv8jhv89isc9wzf5jalsfpsg5y0l9nqcbq0b";
  -  };
  -  pkgs = import (pkgsSrc) {};
  +    url = "https://github.com/NixOS/nixpkgs/archive/dc8c798e5db19534e0a9549b7b2c4e76ccf6b8c3.zip";
  +    sha256 = "0272pnng388da5rpdkallc28nxjs5198hfp0ww9j33bl2ghvvai8";
  +  };
   
     jre = pkgs.jre;
     zip = pkgs.zip;
  
positive.code:     name = "hsluv-js";
      builder = builtins.toFile "builder.sh" "
        source $stdenv/setup
        $jre/bin/java -jar $closureCompiler/share/java/compiler.jar \\
           --js_output_file=$out --compilation_level ADVANCED $jsFile
      ";
    };
  
negative.code:     exportsJs = ./javascript/exports.js;
      builder = builtins.toFile "builder.sh" ''
        source $stdenv/setup
        $haxe/bin/haxe -cp $haxeSrc ${targets} -js compiled.js -D js-classic -D js-unflatten
  
        echo '(function() {' > $out
        cat compiled.js >> $out
  