JFR prints IllegalReflectiveAccess warning on startup

Description

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.codehaus.groovy.reflection.CachedClass (file:/app/jenkins/WEB-INF/lib/groovy-all-2.4.21.jar) to method java.lang.Object.finalize()
WARNING: Please consider reporting this to the maintainers of org.codehaus.groovy.reflection.CachedClass
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
Started

Contributor guide

Tech stack

java

Domain

cli

Issue type

bug

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

3

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

half day

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

stale

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

clear

Prerequisites

JavaGroovyJVM module system

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

55

Research direction

Investigate the startup sequence in the Jenkinsfile Runner, particularly how Groovy is loaded. Look for any use of reflection in the Groovy libraries or the application code. Consider adding JVM flags like add opens to suppress the warning. Check the build configuration for JDK version compatibility. Review similar issues in Jenkins core to see how they resolved reflective access warnings.