anchor.diff:        chmod 755 $out/bin/micropolis
       '';
   
  -  meta = { 
  +  meta = {
       description = "GPL'ed version of S*m C*ty";
       homepage = http://www.donhopkins.com/home/micropolis/;
       license = "GPL";
  
positive.code:   patches =
      [ (fetchurl {
          url = http://rmdir.de/~michael/micropolis_git.patch;
          sha256 = "13419a4394242cd11d5cabd8b1b50787282ea16b55fdcfbeadf8505af46b0592";
        })
      ];
  
  
negative.code: { stdenv, fetchurl, libX11, libXpm, libXext, xextproto, byacc }:
  
  stdenv.mkDerivation {
    name = "micropolis-2010-12-18"; # version from the patch timestamp
  
    src = fetchurl {
      url = http://www.donhopkins.com/home/micropolis/micropolis-activity-source.tgz;
  