anchor.diff:  , libusb ? null, gnutls ? null, avahi ? null, libpaper ? null
   }:
   
  -let version = "2.1.2"; in
  +let version = "2.0.4"; in
   
   with stdenv.lib;
   stdenv.mkDerivation {
  
positive.code: 
    src = fetchurl {
      url = "https://www.cups.org/software/${version}/cups-${version}-source.tar.bz2";
      sha256 = "1bc1y8fjgh54ryh520gk63i5rbagn6jijsrskcqlibhfm0xwmc5s";
    };
  
    buildInputs = [ pkgconfig zlib libjpeg libpng libtiff libusb gnutls libpaper ]
  
negative.code:       # Idem for /etc.
        "PAMDIR=$(out)/etc/pam.d"
        "DBUSDIR=$(out)/etc/dbus-1"
        "INITDIR=$(out)/etc/rc.d"
        "XINETD=$(out)/etc/xinetd.d"
        "SERVERROOT=$(out)/etc/cups"
        # Idem for /usr.
  