anchor.diff:      "--enable-snmp-rfcv3"
       "--enable-dbus"
       "--enable-sha1"
  +    "--enable-json"
     ];
   
     preInstall = ''
  
positive.code:     glib
      ipset
      iptables
      libnfnetlink
      libnl
      net-snmp
  
negative.code: }:
  
  let
    version = "1.3.9";
  in
  stdenv.mkDerivation rec {
    name = "keepalived-${version}";
  
    src = fetchurl {
      url = "http://keepalived.org/software/${name}.tar.gz";
      multihash = "QmQkPJLuWbH9EtVAqJowM9atAaCKGn1xUgBJu2RSVZSqoJ";
      sha256 = "d5bdd25530acf60989222fd92fbfd596e06ecc356a820f4c1015708b76a8d4f3";
    };
  
    nativeBuildInputs = [
  