The following test failed in an Adhoc Mach5 job set:

jdk/jfr/event/oldobject/TestLargeRootSet.java

Here's a snippet from the log file:

#section:main
----------messages:(5/359)----------
command: main -XX:TLABSize=2k jdk.jfr.event.oldobject.TestLargeRootSet
reason: User specified action: run main/othervm -XX:TLABSize=2k jdk.jfr.event.oldobject.TestLargeRootSet
Mode: othervm [/othervm specified]
Additional options from @modules: --add-modules jdk.jfr --add-exports jdk.jfr/jdk.jfr.internal.test=ALL-UNNAMED
elapsed time (seconds): 4.944
----------configuration:(4/119)----------
Boot Layer
  add modules: jdk.jfr
  add exports: jdk.jfr/jdk.jfr.internal.test ALL-UNNAMED

----------System.out:(23/1465)*----------
# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc: SuppressErrorAt=\\edgeStore.cpp:291
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (t:\\workspace\\open\\src\\hotspot\\share\\jfr\\leakprofiler\\chains\\edgeStore.cpp:291), pid=30736, tid=34708
# assert(!contains(edge->reference())) failed: invariant
#
# JRE version: Java(TM) SE Runtime Environment (18.0) (fastdebug build 18-internal+0-2021-11-01-1849543.daniel.daugherty.8249004forjdk18.git)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 18-internal+0-2021-11-01-1849543.daniel.daugherty.8249004forjdk18.git, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, windows-amd64)
# Core dump will be written. Default location: T:\\testoutput\\test-support\\jtreg_open_test_jdk_jdk_jfr\\scratch\\0\\hs_err_pid30736.mdmp
#
# JFR recording file will be written. Location: T:\\testoutput\\test-support\\jtreg_open_test_jdk_jdk_jfr\\scratch\\0\\hs_err_pid30736.jfr
#
# An error report file with more information is saved as:
# T:\\testoutput\\test-support\\jtreg_open_test_jdk_jdk_jfr\\scratch\\0\\hs_err_pid30736.log

[error occurred during error reporting (), id 0xe0000000, Internal Error (t:\\workspace\\open\\src\\hotspot\\share\\runtime/thread.hpp:1441)]

#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#
----------System.err:(0/0)----------
----------rerun:(44/6618)*----------


Here's the crashing thread's stack:

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

Current thread (0x000001a48fce0b80): VMThread "VM Thread" [stack: 0x00000085cbd00000,0x00000085cbe00000] [id=34708]

Stack: [0x00000085cbd00000,0x00000085cbe00000]
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [jvm.dll+0xb55b81] os::platform_print_native_stack+0xf1 (os_windows_x86.cpp:235)
V [jvm.dll+0xd92cee] VMError::report+0x101e (vmError.cpp:828)
V [jvm.dll+0xd946ee] VMError::report_and_die+0x7fe (vmError.cpp:1656)
V [jvm.dll+0xd94e74] VMError::report_and_die+0x64 (vmError.cpp:1437)
V [jvm.dll+0x4defb7] report_vm_error+0xb7 (debug.cpp:282)
V [jvm.dll+0x56e953] EdgeStore::put_chain+0x113 (edgeStore.cpp:309)
V [jvm.dll+0x54b53d] DFSClosure::add_chain+0x2ad (dfsClosure.cpp:133)
V [jvm.dll+0x54b920] DFSClosure::closure_impl+0x390 (dfsClosure.cpp:101)
V [jvm.dll+0x54ba88] DFSClosure::do_root+0xa8 (dfsClosure.cpp:158)
V [jvm.dll+0xc00bd3] RootSetClosure<DFSClosure>::do_oop+0xf3 (rootSetClosure.cpp:51)
V [jvm.dll+0x461248] ClassLoaderData::ChunkedHandleList::oops_do_chunk+0x58 (classLoaderData.cpp:212)
V [jvm.dll+0x4610ec] ClassLoaderData::ChunkedHandleList::oops_do+0x3c (classLoaderData.cpp:224)
V [jvm.dll+0x462d58] ClassLoaderDataGraph::always_strong_cld_do+0x58 (classLoaderDataGraph.cpp:286)
V [jvm.dll+0xc00d28] RootSetClosure<DFSClosure>::process+0x48 (rootSetClosure.cpp:72)
V [jvm.dll+0x54bcf5] DFSClosure::find_leaks_from_root_set+0xd5 (dfsClosure.cpp:69)
V [jvm.dll+0xb88e76] PathToGcRootsOperation::doit+0x306 (pathToGcRootsOperation.cpp:125)
V [jvm.dll+0xd9a589] VM_Operation::evaluate+0xb9 (vmOperations.cpp:71)
V [jvm.dll+0xd9c494] VMThread::evaluate_operation+0xa4 (vmThread.cpp:283)
V [jvm.dll+0xd9cbb5] VMThread::inner_execute+0x255 (vmThread.cpp:432)
V [jvm.dll+0xd9cf40] VMThread::run+0x160 (vmThread.cpp:175)
V [jvm.dll+0xd0bbc4] Thread::call_run+0x1b4 (thread.cpp:365)
V [jvm.dll+0xb5453e] thread_native_entry+0xae (os_windows.cpp:544)
C [ucrtbase.dll+0x1fb80]
C [KERNEL32.DLL+0x84d4]
C [ntdll.dll+0x51791]

VM_Operation (0x00000085ccafe960): JFROldObject, mode: safepoint, requested by thread 0x000001a4942d4b60