anchor.diff:  }:
   
   stdenv.mkDerivation rec {
  -  name = "dovecot-2.3.0";
  +  name = "dovecot-2.3.0.1";
   
     nativeBuildInputs = [ perl pkgconfig ];
     buildInputs =
  
positive.code: 
    src = fetchurl {
      url = "http://dovecot.org/releases/2.3/${name}.tar.gz";
      sha256 = "10c5myzgys866c3x6jdr1s9x9pqnjd5vpyz8z384sph21m3wnq6y";
    };
  
    preConfigure = ''
  
negative.code:     # so we can symlink plugins from several packages there.
      # The symlinking needs to be done in NixOS.
      ./2.2.x-module_dir.patch
    ];
  
    configureFlags = [
  