"Address already in use" error from ScalaTestWithActorTestKit

[zhenhao (Zhenhao Li)]

@zhenhao

with

extends ScalaTestWithActorTestKit(ConfigFactory.parseString("""
    // akka.persistence.testkit.events.serialize = off
    // akka {
    //   remote {
    //       artery.enabled = on
    //       artery.transport = aeron-udp
    //       artery.canonical.port = 0
    //       artery.canonical.hostname = localhost
    //   }
    // }
    """))

which is just an empty config, I got the following error in my test using ScalaTestWithActorTestKit

[2021-02-08 23:12:45,054] [ERROR] [akka.remote.artery.aeron.ArteryAeronUdpTransport] [] [my-app-akka.actor.default-dispatcher-6] - Aeron error: 1 observations from 02/08/2021 23:12:45.043 to 02/08/2021 23:12:45.043 for:
 io.aeron.exceptions.AeronException: ERROR - channel error - Address already in use (at java.base/sun.nio.ch.Net.bind0(Native Method)): aeron:udp?endpoint=127.0.0.1:2552
        at io.aeron.driver.media.UdpChannelTransport.openDatagramChannel(UdpChannelTransport.java:167)
        at io.aeron.driver.media.ReceiveChannelEndpoint.openChannel(ReceiveChannelEndpoint.java:240)
        at io.aeron.driver.Receiver.onRegisterReceiveChannelEndpoint(Receiver.java:156)
        at io.aeron.driver.ReceiverProxy.lambda$registerReceiveChannelEndpoint$5(ReceiverProxy.java:126)
        at org.agrona.concurrent.OneToOneConcurrentArrayQueue.drain(OneToOneConcurrentArrayQueue.java:116)
        at io.aeron.driver.Receiver.doWork(Receiver.java:77)
        at org.agrona.concurrent.CompositeAgent.doWork(CompositeAgent.java:114)
        at org.agrona.concurrent.AgentRunner.doDutyCycle(AgentRunner.java:291)
        at org.agrona.concurrent.AgentRunner.run(AgentRunner.java:164)
        at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.net.BindException: Address already in use
        at java.base/sun.nio.ch.Net.bind0(Native Method)
        at java.base/sun.nio.ch.Net.bind(Net.java:455)
        at java.base/sun.nio.ch.DatagramChannelImpl.bindInternal(DatagramChannelImpl.java:814)
        at java.base/sun.nio.ch.DatagramChannelImpl.bind(DatagramChannelImpl.java:785)
        at io.aeron.driver.media.UdpChannelTransport.openDatagramChannel(UdpChannelTransport.java:127)
        ... 9 more

and

akka.remote.RemoteTransportException was thrown inside "my-test" when, construction cannot continue: "Inbound Aeron channel is in errored state. See Aeron logs for details."

I was expecting it to work out of the box. what config do I need to pass to ScalaTestWithActorTestKit ?

The cause is that I have implicit val system = ActorSystem("my-app") in my test.
It is fixed by replacing it with implicit val system = testKit.internalSystem.toClassic