anchor.diff:      "--disable-bundled-md5"
       "--disable-dynamic-load"
       "--enable-shared"
  -  ] ++ lib.optional (libmaxminddb != null) "--enable-mmdb"
  -    ++ lib.optional (geolite-legacy != null) "--with-geoip-db=${geolite-legacy}/share/GeoIP"
  -    ++ lib.optional (ip2location-c != null) "--enable-ip2location";
  +  ] ++ lib.optional (libmaxminddb != null) [
  +    "--enable-mmdb"
  +  ] ++ lib.optional (geolite-legacy != null) [
  +    "--with-geoip-db=${geolite-legacy}/share/GeoIP"
  +  ] ++ lib.optional (ip2location-c != null) [
  +    "--enable-ip2location"
  +  ];
   
     enableParallelBuilding = true;
   
  
positive.code: { lib, stdenv, fetchurl, getopt, ip2location-c, openssl, perl
  , libmaxminddb ? null, geolite-legacy ? null }:
  
  stdenv.mkDerivation rec {
    pname = "ipv6calc";
    version = "2.2.0";
  
    src = fetchurl {
      urls = [
        "https://www.deepspace6.net/ftp/pub/ds6/sources/ipv6calc/${pname}-${version}.tar.gz"
        "ftp://ftp.deepspace6.net/pub/ds6/sources/ipv6calc/${pname}-${version}.tar.gz"
        "ftp://ftp.bieringer.de/pub/linux/IPv6/ipv6calc/${pname}-${version}.tar.gz"
      ];
      sha256 = "18acy0sy3n6jcjjwpxskysinw06czyayx1q4rqc7zc3ic4pkad8r";
    };
  
    buildInputs = [ libmaxminddb geolite-legacy getopt ip2location-c openssl perl ];
  
    postPatch = ''
      patchShebangs *.sh */*.sh
  
negative.code:       Now only one utiltity is needed to do a lot.
      '';
      homepage = "http://www.deepspace6.net/projects/ipv6calc.html";
      license = licenses.gpl2Only;
      maintainers = with maintainers; [ ];
      platforms = platforms.linux;
    };
  }
  