Jetstream Dispatcher error: panic: runtime error: invalid memory address or nil pointer dereference

[darylangg]

Describe the bug
When trying to setup channels using the Knative bookstore example, received the error as per title when sending messages into the channel.

Expected behavior
Expected to see the sequence executed and output being passed back via trigger

To Reproduce

• Using configs as per this repo
• Using v1.16 manifest
• Created Sequence as follows:

apiVersion: flows.knative.dev/v1
kind: Sequence
metadata:
  name: sequence
spec:
  channelTemplate: # Under the hood, the Sequence will create a Channel for each step in the Sequence
    apiVersion: messaging.knative.dev/v1alpha1
    kind: NatsJetStreamChannel
  steps:
    - ref: # This is the first step of the Sequence, it will send the event to the bad-word-filter service
        apiVersion: serving.knative.dev/v1
        kind: Service
        name: bad-word-filter
    - ref: # This is the second step of the Sequence, it will send the event to the sentiment-analysis-app service
        apiVersion: serving.knative.dev/v1
        kind: Service
        name: sentiment-analysis-app
  reply: # This is the last step of the Sequence, it will send the event back to the Broker as reply
    ref:
      kind: Broker
      apiVersion: eventing.knative.dev/v1
      name: knative-rabbitmq-broker

• Initially, kubectl get natsjetstreamchannels showed that all channels were ready
• After sending a message, error reported

Knative release version
1.16.0

Observations

• After sending the CE, the message is sent to the first stream KN_DEFAULT__SEQUENCE_KN_SEQUENCE_0. We can observe this by using the nats cli.

kubectl run nats-client --rm -it --image=synadia/nats-box --restart=Never --
nats consumer add --server nats://<nats-server-ip>:4222 --deliver=all

• We can then consume the message

nats consumer next --server nats://<nats-server-ip>:4222 KN_DEFAULT__SEQUENCE_KN_SEQUENCE_0  <consumer-name> --ack

Conclusion
The message is being sent to the NATS stream and stays there, but when the Jetstream Dispatcher attempts to consume the message it seems to throw the error reported.