The following test failed in the JDK20 CI:

applications/kitchensink/Kitchensink.java

Here's a snippet from the log file:

Iteration done: LockDeflation at Fri Dec 09 00:54:37 UTC 2022
Iteration done: MemAccess at Fri Dec 09 00:55:05 UTC 2022
Iteration start: Allocator at Fri Dec 09 00:55:34 UTC 2022
# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc: SuppressErrorAt=/g1CollectionSetCandidates.cpp:89


The tail of stress stdout is:
For random generator using seed: -6686853612947720509
To re-run test with same seed value please add "-Djdk.test.lib.random.seed=-6686853612947720509" to command line.
Stress process main method is started.
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/opt/mach5/mesos/work_dir/slaves/0c72054a-24ab-4dbb-944f-97f9341a1b96-S151567/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/e6ab6acc-93bd-47e9-996b-765d57942cd5/runs/078a5a82-9b55-431d-823f-ef5dd283ff67/workspace/open/src/hotspot/share/gc/g1/g1CollectionSetCandidates.cpp:89), pid=3177614, tid=3177624
# guarantee((cur->is_pinned() && !cur->is_archive()) || G1CollectionSetChooser::should_add(cur)) failed: Region 1851 should be eligible for addition.
#
# JRE version: Java(TM) SE Runtime Environment (20.0+27) (fastdebug build 20-ea+27-2213)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 20-ea+27-2213, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, linux-aarch64)
# Problematic frame:
# V [libjvm.so+0xc30eb4] G1CollectionSetCandidates::verify() const+0x1e0
#
# 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/0c72054a-24ab-4dbb-944f-97f9341a1b96-S151471/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/84dc707f-96b0-48a3-b55e-c6d9c4326996/runs/897f0528-6877-42e6-bab9-2e8ce91c5a8c/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_kitchensink_Kitchensink_java/scratch/0/core.3177614)
#
Unsupported internal testing APIs have been used.

# An error report file with more information is saved as:
# /opt/mach5/mesos/work_dir/slaves/0c72054a-24ab-4dbb-944f-97f9341a1b96-S151471/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/84dc707f-96b0-48a3-b55e-c6d9c4326996/runs/897f0528-6877-42e6-bab9-2e8ce91c5a8c/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_kitchensink_Kitchensink_java/scratch/0/hs_err_pid3177614.log
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#
----------System.err:(207/23348)----------


Here's the crashing thread's stack:

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

Current thread (0x0000fffd68284d60): VMThread "VM Thread" [stack: 0x0000fffd395c0000,0x0000fffd397c0000] [id=3177624]

Stack: [0x0000fffd395c0000,0x0000fffd397c0000], sp=0x0000fffd397bdbd0, free space=2038k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0xc30eb4] G1CollectionSetCandidates::verify() const+0x1e0 (g1CollectionSetCandidates.cpp:89)
V [libjvm.so+0xc2df84] G1CollectionSet::finalize_old_part(double)+0x274 (g1CollectionSet.cpp:371)
V [libjvm.so+0xd1ee50] G1YoungCollector::pre_evacuate_collection_set(G1EvacInfo*)+0xb0 (g1YoungCollector.cpp:273)
V [libjvm.so+0xd1ffec] G1YoungCollector::collect()+0x248 (g1YoungCollector.cpp:1085)
V [libjvm.so+0xc1e650] G1CollectedHeap::do_collection_pause_at_safepoint_helper()+0x90 (g1CollectedHeap.cpp:2874)
V [libjvm.so+0xc1e780] G1CollectedHeap::do_collection_pause_at_safepoint()+0xb0 (g1CollectedHeap.cpp:2794)
V [libjvm.so+0xd1d29c] VM_G1CollectForAllocation::doit()+0x48 (g1VMOperations.cpp:148)
V [libjvm.so+0x18c7ea8] VM_Operation::evaluate()+0x158 (vmOperations.cpp:71)
V [libjvm.so+0x18f1c28] VMThread::evaluate_operation(VM_Operation*)+0x118 (vmThread.cpp:281)
V [libjvm.so+0x18f3538] VMThread::inner_execute(VM_Operation*)+0x4b8 (vmThread.cpp:428)
V [libjvm.so+0x18f3694] VMThread::loop()+0xc4 (vmThread.cpp:495)
V [libjvm.so+0x18f37bc] VMThread::run()+0xc8 (vmThread.cpp:175)
V [libjvm.so+0x17d8118] Thread::call_run()+0xf8 (thread.cpp:224)
V [libjvm.so+0x14f0914] thread_native_entry(Thread*)+0x100 (os_linux.cpp:739)
C [libpthread.so.0+0x7908] start_thread+0x188