anchor.diff:      (mkFlag true                      "rsyslogd")
       (mkFlag true                      "mail")
       (mkFlag (liblognorm != null)      "mmnormalize")
  +    (mkFlag (libmaxminddb != null)    "mmdblookup")
       (mkFlag true                      "mmjsonparse")
       (mkFlag true                      "mmaudit")
       (mkFlag true                      "mmanon")
  
positive.code:     fastJson libestr json_c zlib pythonPackages.docutils libkrb5 jemalloc
      postgresql libdbi net-snmp libuuid curl gnutls libgcrypt liblognorm openssl
      librelp libksi liblogging libnet hadoop rdkafka libmongo-client czmq
      rabbitmq-c hiredis mongoc
    ] ++ stdenv.lib.optional (libmysqlclient != null) libmysqlclient
      ++ stdenv.lib.optional stdenv.isLinux systemd;
  
  
negative.code: , libgcrypt ? null, liblognorm ? null, openssl ? null, librelp ? null, libksi ? null
  , liblogging ? null, libnet ? null, hadoop ? null, rdkafka ? null
  , libmongo-client ? null, czmq ? null, rabbitmq-c ? null, hiredis ? null, mongoc ? null
  , libmaxminddb ? null
  }:
  
  with stdenv.lib;
  