What Debezium connector do you use and what version?

MySQL connector, 2.3.0-SNAPSHOT

What is the connector configuration?

"read.only": "true"

What behaviour do you expect?

Incremental snapshots are expected to work

What behaviour do you see?

org.apache.kafka.connect.errors.ConnectException: An exception occurred in the change event producer. This connector will be stopped.
 at io.debezium.pipeline.ErrorHandler.setProducerThrowable(ErrorHandler.java:72)
 at io.debezium.pipeline.ChangeEventSourceCoordinator.lambda$start$0(ChangeEventSourceCoordinator.java:128)
 at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539)
 at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
 at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
 at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
 at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.NullPointerException: Cannot invoke "org.apache.kafka.clients.consumer.KafkaConsumer.seek(org.apache.kafka.common.TopicPartition, long)" because "this.signalsConsumer" is null
 at io.debezium.pipeline.signal.channels.KafkaSignalChannel.seek(KafkaSignalChannel.java:124)
 at io.debezium.connector.mysql.MySqlReadOnlyIncrementalSnapshotChangeEventSource.init(MySqlReadOnlyIncrementalSnapshotChangeEventSource.java:101)
 at io.debezium.connector.mysql.MySqlReadOnlyIncrementalSnapshotChangeEventSource.init(MySqlReadOnlyIncrementalSnapshotChangeEventSource.java:78)
 at io.debezium.pipeline.ChangeEventSourceCoordinator.lambda$initStreamEvents$3(ChangeEventSourceCoordinator.java:210)
 at java.base/java.util.Optional.ifPresent(Optional.java:178)
 at io.debezium.pipeline.ChangeEventSourceCoordinator.initStreamEvents(ChangeEventSourceCoordinator.java:210)
 at io.debezium.pipeline.ChangeEventSourceCoordinator.streamEvents(ChangeEventSourceCoordinator.java:194)
 at io.debezium.pipeline.ChangeEventSourceCoordinator.executeChangeEventSources(ChangeEventSourceCoordinator.java:163)
 at io.debezium.pipeline.ChangeEventSourceCoordinator.lambda$start$0(ChangeEventSourceCoordinator.java:121)
 ... 5 more

Do you see the same behaviour using the latest relesead Debezium version?

Released versions aren't affected, only the latest snapshot

How to reproduce the issue using our tutorial deployment?

The issue occurs on read-only MySQL connector start up