The enricher shouldn't ever produce a stack trace like this, even if something is broken. Listeners need to be hardened. 

 
ava.lang.NullPointerException
at io.jenkins.blueocean.rest.factory.BluePipelineFactory.resolve(BluePipelineFactory.java:64)
at io.jenkins.blueocean.service.embedded.LinkResolverImpl.resolveJob(LinkResolverImpl.java:50)
at io.jenkins.blueocean.service.embedded.LinkResolverImpl.resolve(LinkResolverImpl.java:30)
at io.jenkins.blueocean.rest.hal.LinkResolver.resolveLink(LinkResolver.java:32)
at io.jenkins.blueocean.events.BlueMessageEnricher.enrich(BlueMessageEnricher.java:74)
at org.jenkinsci.plugins.pubsub.PubsubBus.publish(PubsubBus.java:133)
Caused: org.jenkinsci.plugins.pubsub.MessageException: Event enrichment failure due to unexpected exception in io.jenkins.blueocean.events.BlueMessageEnricher.
at org.jenkinsci.plugins.pubsub.PubsubBus.publish(PubsubBus.java:135)
at com.cloudbees.analytics.events.CheckoutEventListener.onCheckout(CheckoutEventListener.java:121)
at org.jenkinsci.plugins.workflow.steps.scm.SCMStep.checkout(SCMStep.java:127)
at org.jenkinsci.plugins.workflow.steps.scm.SCMStep$StepExecutionImpl.run(SCMStep.java:85)
at org.jenkinsci.plugins.workflow.steps.scm.SCMStep$StepExecutionImpl.run(SCMStep.java:75)
at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1$1.call(AbstractSynchronousNonBlockingStepExecution.java:47)
at hudson.security.ACL.impersonate(ACL.java:260)
at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1.run(AbstractSynchronousNonBlockingStepExecution.java:44)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:748)
Finished: FAILURE