The following test failed in the JDK21 CI:

java/foreign/enablenativeaccess/TestEnableNativeAccess.java

Here's a snippet from the log file:

Trying to get downcall handle
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/opt/mach5/mesos/work_dir/slaves/741e9afd-8c02-45c3-b2e2-9db1450d0832-S100405/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/2d00c4b2-f914-48bf-a896-77cb88ae6dcc/runs/3b07c88a-d7ff-4e72-bc2e-ca9822f65ad8/workspace/open/src/hotspot/share/runtime/jniHandles.cpp:207), pid=2641771, tid=2641797
# Error: ShouldNotReachHere()
#
# JRE version: Java(TM) SE Runtime Environment (21.0+23) (fastdebug build 21-ea+23-LTS-1901)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 21-ea+23-LTS-1901, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, linux-aarch64)
# Problematic frame:
# V [libjvm.so+0xe659f0] JNIHandles::handle_type(JavaThread*, _jobject*)+0xa0
#
# Core dump will be written. Default location: Core dumps may be processed with "/opt/core.sh %p" (or dumping to /opt/mach5/mesos/work_dir/slaves/741e9afd-8c02-45c3-b2e2-9db1450d0832-S96156/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/2db6bc86-bd04-4600-bbdd-1e25991039a0/runs/e229eb84-eb63-4678-a1c1-62a2bcddd379/testoutput/test-support/jtreg_open_test_jdk_tier1/scratch/3/core.2641771)
#
# An error report file with more information is saved as:
# /opt/mach5/mesos/work_dir/slaves/741e9afd-8c02-45c3-b2e2-9db1450d0832-S96156/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/2db6bc86-bd04-4600-bbdd-1e25991039a0/runs/e229eb84-eb63-4678-a1c1-62a2bcddd379/testoutput/test-support/jtreg_open_test_jdk_tier1/scratch/3/hs_err_pid2641771.log
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#


[2023-05-11T17:12:29.467398768Z] Waiting for completion for process 2641771
[2023-05-11T17:12:29.467481609Z] Waiting for completion finished for process 2641771
test TestEnableNativeAccess.testSucceed("panama_enable_native_access_jni", "panama_module/org.openjdk.foreigntest.PanamaMainJNI", success, [Ljava.lang.String;@5c760629): failure
java.lang.AssertionError: expected [true] but found [false]
at org.testng.Assert.fail(Assert.java:99)
at org.testng.Assert.failNotEquals(Assert.java:1037)
at org.testng.Assert.assertTrue(Assert.java:45)
at org.testng.Assert.assertTrue(Assert.java:55)
at TestEnableNativeAccess.checkResult(TestEnableNativeAccess.java:162)
at TestEnableNativeAccess.run(TestEnableNativeAccess.java:186)
at TestEnableNativeAccess.testSucceed(TestEnableNativeAccess.java:192)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:132)
at org.testng.internal.TestInvoker.invokeMethod(TestInvoker.java:599)
at org.testng.internal.TestInvoker.invokeTestMethod(TestInvoker.java:174)
at org.testng.internal.MethodRunner.runInSequence(MethodRunner.java:46)
at org.testng.internal.TestInvoker$MethodInvocationAgent.invoke(TestInvoker.java:822)
at org.testng.internal.TestInvoker.invokeTestMethods(TestInvoker.java:147)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:146)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:128)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1593)
at org.testng.TestRunner.privateRun(TestRunner.java:764)
at org.testng.TestRunner.run(TestRunner.java:585)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:384)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:378)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:337)
at org.testng.SuiteRunner.run(SuiteRunner.java:286)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:53)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:96)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1218)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1140)
at org.testng.TestNG.runSuites(TestNG.java:1069)
at org.testng.TestNG.run(TestNG.java:1037)
at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:102)
at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:58)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
at java.base/java.lang.Thread.run(Thread.java:1583)

Here's the crashing thread's stack trace:

--------------- T H R E A D ---------------

Current thread (0x0000fffebc000b70): JavaThread "Thread-0" [_thread_in_vm, id=2641797, stack(0x0000fffecb440000,0x0000fffecbc40000) (8192K)]

Stack: [0x0000fffecb440000,0x0000fffecbc40000], sp=0x0000fffecbc3e730, free space=8185k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0xe659f0] JNIHandles::handle_type(JavaThread*, _jobject*)+0xa0 (jniHandles.cpp:207)
V [libjvm.so+0xe4a454] jniCheck::validate_handle(JavaThread*, _jobject*)+0x24 (jniCheck.cpp:425)
V [libjvm.so+0xe4abc0] jniCheck::validate_object(JavaThread*, _jobject*)+0x50 (jniCheck.cpp:453)
V [libjvm.so+0xe53014] jniCheck::validate_call(JavaThread*, _jclass*, _jmethodID*, _jobject*) [clone .constprop.0]+0x64 (jniCheck.cpp:528)
V [libjvm.so+0xe562c8] checked_jni_CallVoidMethodV+0xb8 (jniCheck.cpp:1011)
C [libLinkerInvokerModule.so+0xc70] JNIEnv_::CallVoidMethod(_jobject*, _jmethodID*, ...)+0x70 (jni.h:1064)
C [libLinkerInvokerModule.so+0xacc] call(void*)+0x7c (libLinkerInvokerModule.cpp:42)
C [libLinkerInvokerModule.so+0xa40] procedure+0x10 (testlib_threads.h:62)
C [libpthread.so.0+0x7908] start_thread+0x188