nixpkgs/pkgs/development/libraries/expat/default.nix

{stdenv, fetchurl}: stdenv.mkDerivation {
  name = "expat-2.0.1";
  src = fetchurl {
    url = mirror://sourceforge/expat/expat-2.0.1.tar.gz;
    sha256 = "14sy5qx9hgjyfs743iq8ywldhp5w4n6cscqf2p4hgrw6vys60xl4";
  };
}