anchor.diff:        libXext libXScrnSaver libX11 libXrandr libXmu libXxf86vm libXrender
         libXxf86misc
       ];
  +
  +  patchPhase =
  +    ''
  +      # Fix build error in version 5.18. Remove this patch when updating
  +      # to a later version.
  +      sed -i -e '/AF_LINK/d' hacks/glx/sonar-icmp.c
  +      # Fix path to GTK.
  +      sed -e 's%@GTK_DATADIR@%@datadir@% ; s%@PO_DATADIR@%@datadir@%' \
  +	  -i driver/Makefile.in po/Makefile.in.in
  +    '';
   
     configureFlags =
       [ "--with-gl" "--with-pam" "--with-pixbuf" "--with-proc-interrupts"
  
positive.code: { stdenv, fetchurl, pkgconfig, bc, perl, pam
  , libXext, libXScrnSaver, libX11, libXrandr, libXmu, libXxf86vm, libXrender
  , libXxf86misc
  , libjpeg, mesa, gtk, libxml2, libglade
  }:
  
  stdenv.mkDerivation rec {
    version = "5.15";
    name = "xscreensaver-${version}";
  
    src = fetchurl {
      url = "http://www.jwz.org/xscreensaver/${name}.tar.gz";
      sha256 = "4f6d1f1e4c15dbb74e2296f8fe57a73d47d602515178c248bbc838f779d5082d";
    };
  
    buildInputs =
  
negative.code:       "--with-x-app-defaults=\${out}/share/xscreensaver/app-defaults"
      ];
  
    meta = {
      homepage = "http://www.jwz.org/xscreensaver/";
      description = "A set of screensavers";
  