Jenkins pipeline throws "StackOverflowError: Excessively nested closures/functions"

Question

I have following Jenkinsfile:

#!groovy

def projectPath = "${projectPath}"
def specPath = "${specPath}"
int numberOfRetries = "${NUM_OF_RETRIES}".toInteger()

def failure = true
def retryAmount = 0
def start = System.currentTimeMillis()

def getSpecName() {
    specPath.split("/")[-1].split(".")[0]
}

def getProjectPath() {
    projectPath.split("/")[-1]
}

def rmDocker() {
    def remove = sh script: "docker rm -f cypress_${getSpecName()}", returnStatus: true
}

stage("Cypress Setup") {
    node("Cypress") {
        rmDocker()
    }
}

stage("Cypress Run") {
    node("Cypress") {
        currentBuild.setDisplayName("${projectPath} - ${getSpecName()}")
        while (failure && retryAmount < numberOfRetries) {
            sh "docker pull dockreg.bluestembrands.com/cypresswithtests:latest"
            if (getSpecName().toLowerCase().contains("auth")) {
                exit_code = sh script:"docker run --name cypress_${getSpecName()} dockreg.bluestembrands.com/cypresswithtests:latest sh -c \"node SQLSite/request.js & cypress run -P ${projectPath} --spec ${specPath} --env RUN=${retryAmount} --config videoCompression=${videoCompression} --reporter /usr/local/lib/node_modules/mochawesome-cypress-bsb --reporter-options \"reportDir=mochawesome-reports/run${retryAmount}/, reportName=mochawesome\"\"", returnStatus: true    
            } else {
                exit_code = sh script:"docker run --name cypress_${getSpecName()} dockreg.bluestembrands.com/cypresswithtests:latest sh -c \"cypress run -P ${projectPath} --spec ${specPath} --env RUN=${retryAmount} --config videoCompression=${videoCompression} --reporter /usr/local/lib/node_modules/mochawesome-cypress-bsb --reporter-options \"reportDir=mochawesome-reports/run${retryAmount}/, reportName=mochawesome\"\"", returnStatus: true  
            }
            failure = exit_code != 0
            try {
                println "/var/docker-mounts/nfs/qa/test-results/${getProjectPath()}-${getSpecName()}/"
                dir("/var/docker-mounts/nfs/qa/test-results/${getProjectPath()}-${getSpecName()}/") {
                    sh "docker cp cypress_${getSpecName()}:/cypress/${projectPath}/mochawesome-reports /var/docker-mounts/nfs/qa/test-results/${getProjectPath()}-${getSpecName()}/${BUILD_ID}"
                }
            } catch (Exception e) {
                println e
                echo "Failed to copy Mochawesome tests"
            }
            rmDocker()
            retryAmount++
        }
    }

    if (failure) {
        currentBuild.result = "FAILURE"
    }
}

It throws following exception when I try to run it:

java.lang.StackOverflowError: Excessively nested closures/functions at WorkflowScript.getProjectPath(WorkflowScript:16) - look for unbounded recursion - call depth: 1025
    at com.cloudbees.groovy.cps.impl.CpsFunction.invoke(CpsFunction.java:28)
    at com.cloudbees.groovy.cps.impl.CpsCallableInvocation.invoke(CpsCallableInvocation.java:40)
    at com.cloudbees.groovy.cps.impl.ContinuationGroup.methodCall(ContinuationGroup.java:62)
    at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.dispatchOrArg(FunctionCallBlock.java:109)
    at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.fixName(FunctionCallBlock.java:77)
    at sun.reflect.GeneratedMethodAccessor345.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)
    at com.cloudbees.groovy.cps.impl.ConstantBlock.eval(ConstantBlock.java:21)
    at com.cloudbees.groovy.cps.Next.step(Next.java:83)
    at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:174)
    at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:163)
    at org.codehaus.groovy.runtime.GroovyCategorySupport$ThreadCategoryInfo.use(GroovyCategorySupport.java:122)
    at org.codehaus.groovy.runtime.GroovyCategorySupport.use(GroovyCategorySupport.java:261)
    at com.cloudbees.groovy.cps.Continuable.run0(Continuable.java:163)
    at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.access$101(SandboxContinuable.java:34)
    at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.lambda$run0$0(SandboxContinuable.java:59)
    at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.GroovySandbox.runInSandbox(GroovySandbox.java:108)
    at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.run0(SandboxContinuable.java:58)
    at org.jenkinsci.plugins.workflow.cps.CpsThread.runNextChunk(CpsThread.java:174)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:332)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$200(CpsThreadGroup.java:83)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:244)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:232)
    at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:64)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:131)
    at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
    at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:59)
    at java.util.concurrent.Executors$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)

The variables are:

NUM_OF_RETRIES: 3

specPath: bsb-haband-web/hab-shop/cypress/integration/Search/SearchNoResultsSpec.js

VideoCompression: false

projectPath: bsb-haband-web/hab-shop

BRANCH_NAME: master

I don't understand where the recursion call is happening as getProjectPath just does a standard split call.

I have tried changing it to .tokenize(), but it still fails.

It might be of note that more than one of these can run at the same times, however the error occurs even if run in isolation.

Could you please help me understanding why this StackOverflowError happens?

Answer 1

Calling getProjectPath() method causes this exception. It happens, because if Groovy finds a getter method for a field foo like getFoo() it fallbacks to execute this method anytime it sees accessing foo value.

What does it mean in your case? When you call the method

def getProjectPath() {
    projectPath.split("/")[-1]
}

it runs into infinite recursion because this method is seen as:

def getProjectPath() {
    getProjectPath().split("/")[-1]
}

so it never reaches .split("/")[-1] - that is why replacing it with tokenize() method didn't change a thing.

Solution: rename getProjectPath() method or projectPath variable name.

Groovy class properties

A property is an externally visible feature of a class. Rather than just using a public field to represent such features (which provides a more limited abstraction and would restrict refactoring possibilities), the typical convention in Java is to follow JavaBean conventions, i.e. represent the property using a combination of a private backing field and getters/setters.

Source: http://groovy-lang.org/objectorientation.html#properties

This part of Groovy's documentation explains this behavior. It can be simplified to an example - a class like:

class Person {
    String name
}

is compiled to something like this:

class Person {
    private String name

    void setName(String name) {
        this.name = name
    }

    String getName() {
        return this.name
    }
}

The general rule of thumb when working with Groovy is that when you specify a field foo you implement getFoo() carefully (if you actually have to do it). Especially you avoid accessing field foo inside this method, because it runs into this infinite recursive call issue.