text: var nijs = require('nijs');
  
  exports.pkg = function(args) {
    return args.stdenv().mkDerivation({
      name : "zlib-1.2.11",
      src : args.fetchurl()({
        url : new nijs.NixURL("mirror://sourceforge/libpng/zlib/1.2.11/zlib-1.2.11.tar.gz"),
        sha256 : "18dighcs333gsvajvvgqp8l4cx7h1x7yx9gd5xacnk80spyykrf3"
      }),
      configureFlags : "--shared"
    });
  };
  