Since https://github.com/apache/storm/pull/810 it is no longer possible to call Testing.completeTopology when time is not simulating, because a call to advance-cluster-time is made from the function, which calls Time/advanceTime. advance-cluster-time should only be called if time is simulating.
Since https://github.com/apache/storm/pull/830 a local cluster run without time simulation may lose messages. When a worker emits messages for a worker that hasn't started yet, the message is lost. This can happen because spouts may start emitting before all workers have started, when time simulation is disabled. Local clusters usually run without message timeouts, so this will make tests relying on Testing.withLocalCluster flaky.
The problem is that there are no longer any queues to store messages for workers that haven't started yet. See https://github.com/apache/storm/pull/830/files#diff-c6ff4208ef84c7a5a1a6b8b6bd1f7d19R104. A queue should be added for messages for workers that haven't registered a receive callback yet.