anchor.diff:  
   stdenv.mkDerivation rec {
     pname = "spidermonkey";
  -  version = "78.4.0";
  +  version = "78.8.0";
   
     src = fetchurl {
       url = "mirror://mozilla/firefox/releases/${version}esr/source/firefox-${version}esr.source.tar.xz";
  -    sha256 = "1z3hj45bnd12z3g6ajv9qrgclca7fymi1sxj9l9nh9q6y6xz0g4f";
  +    sha256 = "0451hhjrj9hb6limxim7sbhvw4gs6dd2gmnfxjjx07z3wbgdzwhw";
     };
   
     outputs = [ "out" "dev" ];
  
positive.code: 
    enableParallelBuilding = true;
  
    meta = with lib; {
      description = "Mozilla's JavaScript engine written in C/C++";
      homepage = "https://developer.mozilla.org/en/SpiderMonkey";
      license = licenses.gpl2; # TODO: MPL/GPL/LGPL tri-license.
      maintainers = with maintainers; [ abbradar lostnet ];
      platforms = platforms.linux;
  
negative.code: { lib, stdenv
  , fetchurl
  , autoconf213
  , pkg-config
  , perl
  