Crash in DPORwHeuristics

[colin-scott]

I'm pretty baffled by this one. After executing a few schedules successfully, DPORwHeuristics crashed with the following:

[ERROR] [04/01/2015 23:10:47.328] [new-system-272-akka.actor.default-dispatcher-10] [akka://new-system-272/user/raft-member-1] null
scala.MatchError: null
        at akka.dispatch.verification.DPORwHeuristics.schedule_new_message(DPORwHeuristics.scala:614)
        at akka.dispatch.verification.Instrumenter.afterMessageReceive(Instrumenter.scala:262)
        at sample.WeaveActor.ajc$after$sample_WeaveActor$3$79e3ab71(WeaveActor.aj:53)
        at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516)
        at akka.actor.ActorCell.invoke(ActorCell.scala:487)
        at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:238)
        at akka.dispatch.Mailbox.run(Mailbox.scala:220)
        at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393)
        at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
        at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
        at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
        at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)