anchor.diff:          PYTHONPATH = "${pkgs.python27Packages.graphite_web}/lib/python2.7/site-packages";
           DJANGO_SETTINGS_MODULE = "graphite.settings";
           GRAPHITE_CONF_DIR = "/etc/graphite/";
  -        GRAPHITE_STORAGE_DIR = "${dataDir}";
  +        GRAPHITE_STORAGE_DIR = dataDir;
         };
         serviceConfig = {
           ExecStart = ''
  
positive.code: let
    cfg = config.services.graphite;
    writeTextOrNull = f: t: if t == null then null else pkgs.writeText f t;
    dataDir = "/var/db/graphite";
  in {
  
    ###### interface
  
negative.code:       description = "Carbon data aggregator";
        wantedBy = [ "multi-user.target" ];
        after = [ "network-interfaces.target" ];
        environment = carbonEnv;
        serviceConfig.ExecStart = "${pkgs.twisted}/bin/twistd ${carbonOpts "carbon-aggregator"}";
        restartTriggers = [
          pkgs.pythonPackages.carbon cfg.carbon.config cfg.carbon.aggregationRules
        ];
  