anchor.diff: -{ stdenv, fetchurl
  +{ stdenv, fetchurl, darwin
   # optional:
   , pkgconfig ? null  # most of the extra deps need pkgconfig to be found
   , curl ? null
  
positive.code:   };
  
    buildInputs = [
      pkgconfig curl iptables libatasmart libcredis libdbi libgcrypt libmemcached
      cyrus_sasl libmodbus libnotify gdk_pixbuf liboping libpcap libsigrok libvirt
      lm_sensors libxml2 lvm2 libmysql postgresql protobufc rabbitmq-c rrdtool
      varnish yajl jdk libtool python udev net_snmp hiredis libmnl libmicrohttpd
    ];
  
    # for some reason libsigrok isn't auto-detected
    configureFlags =
      [ "--localstatedir=/var" ] ++
      stdenv.lib.optional (libsigrok != null) "--with-libsigrok" ++
      stdenv.lib.optional (python != null) "--with-python=${python}/bin/python";
  
    # do not create directories in /var during installPhase
  
negative.code:     description = "Daemon which collects system performance statistics periodically";
      homepage = https://collectd.org;
      license = licenses.gpl2;
      platforms = platforms.unix;
      maintainers = with maintainers; [ bjornfor fpletz ];
    };
  }
  