anchor.diff:  { stdenv, fetchurl, autoreconfHook, openssl, python, findutils }:
   
  -let version = "2.0.22"; in
  -stdenv.mkDerivation {
  +stdenv.mkDerivation rec {
     name = "libevent-${version}";
  +  version = "2.0.22";
   
     src = fetchurl {
       url = "mirror://sourceforge/levent/libevent-${version}-stable.tar.gz";
  
positive.code: 
    meta = with stdenv.lib; {
      description = "Event notification library";
  
      longDescription =
        '' The libevent API provides a mechanism to execute a callback function
           when a specific event occurs on a file descriptor or after a timeout
           has been reached.  Furthermore, libevent also support callbacks due
           to signals or regular timeouts.
  
           libevent is meant to replace the event loop found in event driven
           network servers.  An application just needs to call event_dispatch()
           and then add or remove events dynamically without having to change
           the event loop.
        '';
  
      license = licenses.bsd3;
      platforms = platforms.all;
      maintainers = with maintainers; [ wkennington ];
  
negative.code:   };
  
    nativeBuildInputs = [ autoreconfHook ];
    buildInputs = [ openssl python ];
  
    patchPhase = ''
      patchShebangs event_rpcgen.py
  