anchor.diff:  
     src = fetchurl {
       url = "http://ftp.easysw.com/pub/cups/${version}/cups-${version}-source.tar.bz2";
  -    sha256 = "1xlnkdqldq81pdqgisqbyh92k249bzz35m1f5bp4la06p00ksvjf";
  +    sha256 = "0czc0bmrm31jy03inm6w2mbr5s9q9xk6s1x5x4kddx2qlml9pyf6";
     };
   
     buildInputs = [ pkgconfig zlib libjpeg libpng libtiff pam dbus libusb acl ];
  
positive.code:   meta = {
      homepage = http://www.cups.org/;
      description = "A standards-based printing system for UNIX";
      license = "GPLv2"; # actually LGPL for the library and GPL for the rest
      maintainers = [ stdenv.lib.maintainers.urkud stdenv.lib.maintainers.simons ];
      platforms = stdenv.lib.platforms.linux;
    };
  
negative.code: { stdenv, fetchurl, pkgconfig, zlib, libjpeg, libpng, libtiff, pam, openssl
  , dbus, libusb, acl }:
  
  let version = "1.5.0"; in
  
  stdenv.mkDerivation {
    name = "cups-${version}";
  