code: public void setJvmOutputAction(String jvmOutputActions) {
      EnumSet<JvmOutputAction> actions = EnumSet.noneOf(JvmOutputAction.class); 
      for (String s : jvmOutputActions.split("[\\,\\ ]+")) {
        s = s.trim().toUpperCase(Locale.ROOT);
        actions.add(JvmOutputAction.valueOf(s));
      }
      this.jvmOutputAction = actions;
    }
docs: What should be done on unexpected JVM output? JVM may write directly to the
  original descriptors, bypassing redirections of System.out and System.err. Typically,
  these messages will be important and should fail the build (permgen space exceeded,
  compiler errors, crash dumps). However, certain legitimate logs (gc activity, class loading
  logs) are also printed to these streams so sometimes the output can be ignored.
  
  <p>Allowed values (any comma-delimited combination of): {@link JvmOutputAction}
  constants.