anchor.diff:    src = fetchsvn {
       url = svn://svn.tartarus.org/sgt/putty;
       rev = rev;
  -    sha256 = "f5d9870dde7166afd277f7501914c6515b35ee7bb42965ccd22fe977ee5d1b0d";
  +    sha256 = "e1fb49766e0724a12776ec3d6cd0bd420e03ebdc3383a01a12dbfd30983f81ef";
     };
   
  -  buildInputs = [ gtk ncurses pkgconfig autoconf automake perl halibut ];
  +  buildInputs = [ gtk ncurses pkgconfig autoconf automake perl halibut libtool ];
   }
  
positive.code:   preConfigure = ''
      perl mkfiles.pl
      ( cd doc ; make );
      cd unix
      sed '/AM_PATH_GTK(/d' -i configure.ac
      cp ${automake}/share/automake-*/install-sh .
      autoreconf -vf
    '';
    
    # The hash is going to change on new snapshot.
  
negative.code: { stdenv, fetchsvn, ncurses, gtk, pkgconfig, autoconf, automake, perl, halibut
  , libtool }:
   
  let
    rev = 9690;
  in
  stdenv.mkDerivation {
    name = "putty-${toString rev}";
  