anchor.diff:      nspr
       readline
       zlib
  -  ];
  -
  -  patches = [
  -    # https://mail.gnome.org/archives/distributor-list/2020-August/msg00000.html
  -    (fetchpatch {
  -      url = "https://github.com/ptomato/mozjs/commit/b2974f8a6558d2dc4517b49ee313a9900a853285.patch";
  -      sha256 = "1bl5mbx7gmad6fmpc427263i1ychi2linpg69kxlr2w91r5m6ji3";
  -    })
  -    (fetchpatch {
  -      url = "https://github.com/ptomato/mozjs/commit/e5a2eb99f653ae03c67e536df1d55d265a0a1605.patch";
  -      sha256 = "0xhy63nw2byibmjc41yh6dwpg282nylganrs5aprn9pbqbcpsvif";
  -    })
     ];
   
     preConfigure = ''
  
positive.code: 
  stdenv.mkDerivation rec {
    pname = "spidermonkey";
    version = "78.1.0";
  
    src = fetchurl {
      url = "mirror://mozilla/firefox/releases/${version}esr/source/firefox-${version}esr.source.tar.xz";
      sha256 = "18k47dl9hbnpqw69csxjar5dhwa7r8k7j9kvcfgmwb1iv6ba601n";
    };
  
    outputs = [ "out" "dev" ];
  
negative.code: 
    # Remove unnecessary static lib
    preFixup = ''
      moveToOutput bin/js78-config "$dev"
      rm $out/lib/libjs_static.ajs
      ln -s $out/bin/js78 $out/bin/js
    '';
  
    enableParallelBuilding = true;
  