Unspecified Jenkinsfile Null Pointer Error in Workflow Steps - jenkins

Question

I encountered the following error in a Jenkinsfile pipeline I was building:
java.lang.NullPointerException
at org.jenkinsci.plugins.workflow.steps.CoreStep$Execution.run(CoreStep.java:80)
at org.jenkinsci.plugins.workflow.steps.CoreStep$Execution.run(CoreStep.java:67)
at org.jenkinsci.plugins.workflow.steps.SynchronousNonBlockingStepExecution.lambda$start$0(SynchronousNonBlockingStepExecution.java:47)
at java.util.concurrent.Executors$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$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Finished: FAILURE
The issue here, primarily, is that I'm not sure exactly what is going on. Since all it's mentioning is a null pointer error, I can't exactly be sure, and I can't find anything more specific.
Here's my Jenkinsfile:
#!groovy
node {
withEnv(["WORKSPACE=${pwd()}"]) { //Setting Workspace to the current directory
stage('Clone repository...') {
checkout scm //Let checkout automagically handle pulling in all the names we need and whatnot
}
stage('Building WAR...') {
step(withMaven(
// Maven installation declared in the Jenkins "Global Tool Configuration"
maven: 'Maven 3.6.0') {
// Run the maven build
sh 'mvn clean install' //Same as running on local
sh 'mv ${WORKSPACE}/target/QUserService.war ${WORKSPACE}/target/QUserService_War-QUserService-${BRANCH_NAME}-${BUILD_NUMBER}.war'
//For above line, 'mv' is the Linux command to rename/move files, which is needed for the UCD script
}
// withMaven will discover the generated Maven artifacts, JUnit Surefire & FailSafe & FindBugs reports...
)
}
}
}

Answer 1

So - first, you don't need to define WORKSPACE. It is defined for you by Jenkins. You can convince yourself of this by running sh 'set' on a linux agent.
Next, you don't need to check out the project. It will already be there (assuming you're using a pipeline project).
Next, you don't need to put the withMaven inside of a step call. In a scripted pipeline, the stuff in a stage is groovy script. Step isn't required.
node {
stage('Building WAR...') {
withMaven(
maven: 'Maven 3.5.0') {
// Run the maven build
sh 'mvn clean install' //Same as running on local
}
}
I took out the move step and comment just to make it clearer.
I didn't get a null pointer error. See if removeing the step call and removing the step call make the NPE go away. If not, I'd suggest attaching the console output to attempt to see where this happens.