$ sudo java -jar logstash-1.2.2.dev-flatjar.jar agent -f /etc/logstash/logstash.conf 
Exception in thread "main" java.lang.ClassCastException: java.lang.Object cannot be cast to java.lang.invoke.SwitchPoint
        at org.jruby.runtime.invokedynamic.InvokeDynamicSupport.constantFallback(InvokeDynamicSupport.java:700)
        at logstash.runner.__file__(logstash/runner.rb:2)
        at logstash.runner.load(logstash/runner.rb)
        at logstash.runner.main(logstash/runner.rb)