The following test failed in the JDK21 CI:

runtime/ClassUnload/KeepAliveClassLoader.java

Here's a snippet from the log file:

#section:main
----------messages:(7/509)----------
command: main -Xbootclasspath/a:. -Xmn8m -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI KeepAliveClassLoader
reason: User specified action: run main/othervm -Xbootclasspath/a:. -Xmn8m -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI KeepAliveClassLoader
started: Mon Feb 20 17:17:51 GMT 2023
Mode: othervm [/othervm specified]
Additional options from @modules: --add-modules java.base --add-exports java.base/jdk.internal.misc=ALL-UNNAMED
finished: Mon Feb 20 17:17:52 GMT 2023
elapsed time (seconds): 0.998
----------configuration:(4/111)----------
Boot Layer
  add modules: java.base
  add exports: java.base/jdk.internal.misc ALL-UNNAMED

----------System.out:(3/96)----------
testClassLoader (1) alive: true
testClassLoader (2) alive: true
testClassLoader (3) alive: true
----------System.err:(12/828)----------
jdk.test.lib.classloader.ClassUnloadCommon$TestFailure: Test failed: should be unloaded
at jdk.test.lib.classloader.ClassUnloadCommon.failIf(ClassUnloadCommon.java:51)
at KeepAliveClassLoader.main(KeepAliveClassLoader.java:76)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:125)
at java.base/java.lang.Thread.run(Thread.java:1623)

JavaTest Message: Test threw exception: jdk.test.lib.classloader.ClassUnloadCommon$TestFailure: Test failed: should be unloaded
JavaTest Message: shutting down test

STATUS:Failed.`main' threw exception: jdk.test.lib.classloader.ClassUnloadCommon$TestFailure: Test failed: should be unloaded
----------rerun:(42/10039)*----------