[FIXED] NotSerializableException in jenkinsfile

Issue

I'm working on a jenkinsfile and I'm getting and exception in the third stage:

an exception which occurred:
in field com.cloudbees.groovy.cps.impl.BlockScopeEnv.locals
in object com.cloudbees.groovy.cps.impl.BlockScopeEnv@7bbae4fb
in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
in object com.cloudbees.groovy.cps.impl.CaseEnv@6896a2e3
in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
in object com.cloudbees.groovy.cps.impl.BlockScopeEnv@605ccbbc
in field com.cloudbees.groovy.cps.impl.CallEnv.caller
in object com.cloudbees.groovy.cps.impl.FunctionCallEnv@7b8ef914
in field com.cloudbees.groovy.cps.Continuable.e
in object org.jenkinsci.plugins.workflow.cps.SandboxContinuable@11e73f3c
in field org.jenkinsci.plugins.workflow.cps.CpsThread.program
in object org.jenkinsci.plugins.workflow.cps.CpsThread@b2df9bb
in field org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.threads
in object org.jenkinsci.plugins.workflow.cps.CpsThreadGroup@2b30596a
in object org.jenkinsci.plugins.workflow.cps.CpsThreadGroup@2b30596a
Caused: java.io.NotSerializableException: java.util.regex.Matcher
    at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:860)
    at org.jboss.marshalling.river.BlockMarshaller.doWriteObject(BlockMarshaller.java:65)
    at org.jboss.marshalling.river.BlockMarshaller.writeObject(BlockMarshaller.java:56)

I've been reading about it and I know I can't create non-serializable variables. So, I think it has to be with this part of my code:

def artifact_name = sh (
        script: "ls -b *.jar | head -1",
        returnStdout: true
).trim()
def has_snapshot = artifact_name =~ /-TEST\.jar/
if (has_snapshot) {
    //Do something
}

My question is, how do I define that two variables in order to avoid that exception?

Solution

Your problem is this line:

def has_snapshot = artifact_name =~ /-TEST\.jar/

The =~ is the Groovy find operator. It returns a java.util.regex.Matcher instance, which is not Serializable. If Jenkins decides to pause your script after you have stored the result in a local variable that is serialized by Jenkins that is when you get the exception. This can be easily tested by immediately adding a sleep(1) step after your invocation and watch as that same exception is thrown.

To resolve this, you should :

• Not store the java.util.regex.Matcher result in CPS transformed code
• Move the usage into a @NonCPS annotated method or use the match operator (==~) which returns a boolean (if it fits your use case)

Answered By - mkobit
Answer Checked By - Cary Denson (JavaFixing Admin)