mongodb-metrics.rb check result

check_config

{
  "checks": {
    "mongodb_metrics": {
      "handlers": ["graphite-tcp"],
      "type": "metric",
      "command": "/etc/sensu/plugins/mongodb-metrics.rb --scheme stats.:::name::: ",
      "interval": 15,
      "subscribers": [ "empire-staging" ]
    }
  }
}

checkresult.json

{"timestamp":"2013-04-09T21:46:51.491622+0000","message":"publishing check result",
"payload":{"client":"empire-staging","check":{"name":"mongodb_metrics",
"command":"/etc/sensu/plugins/mongodb-metrics.rb --scheme stats.:::name::: ",
"issued":1365544011,"handlers":["graphite-tcp"],"type":"metric","interval":15,
"subscribers":["empire-staging"],

"output":"/opt/sensu/embedded/lib/ruby/gems/1.9.1/gems/sensu-plugin-0.1.6/lib/sensu-plugin/cli.rb:60:in 
  `rescue in block in <class:CLI>': undefined method `critical' for nil:NilClass (NoMethodError)\n\tfrom 
  /opt/sensu/embedded/lib/ruby/gems/1.9.1/gems/sensu-plugin-0.1.6/lib/sensu-plugin/cli.rb:54:in `block in 
  <class:CLI>'\n",

"status":1,"duration":0.427}},"level":"info","file":"sensu/client.rb","line":"71","method":"publish_result"}