The test gc/stress/systemgc/TestSystemGCWithShenandoah.java#generational has run into the assertion on MacOS aarch64 (2026-02-15):

# Internal Error (jdk/src/hotspot/share/gc/shenandoah/shenandoahMark.inline.hpp:69), pid=18317, tid=12803
# Error: Shenandoah assert_correct failed; Object should be in active region area

Referenced from:
  no interior location recorded (probably a plain heap scan, or detached oop)

Object:
  0x00000007fcdab3c0 - safe print, no details
  region: | 1846|EC |F|BTE 7fcd80000, 7fcd80000, 7fcdc0000|TAMS 7fcd80000|UWM 7fcd80000|U 0B|T 0B|G 0B|P 0B|S 0B|L 0B|CP 0

Raw heap memory:
0x00000007fcdab3a0: baadbabe baadbabe baadbabe baadbabe ................
0x00000007fcdab3b0: baadbabe baadbabe baadbabe baadbabe ................
0x00000007fcdab3c0: baadbabe baadbabe baadbabe baadbabe ................
0x00000007fcdab3d0: baadbabe baadbabe baadbabe baadbabe ................
0x00000007fcdab3e0: baadbabe baadbabe baadbabe baadbabe ................
0x00000007fcdab3f0: baadbabe baadbabe baadbabe baadbabe ................
0x00000007fcdab400: baadbabe baadbabe baadbabe baadbabe ................
0x00000007fcdab410: baadbabe baadbabe baadbabe baadbabe ................
0x00000007fcdab420: baadbabe baadbabe baadbabe baadbabe ................
0x00000007fcdab430: baadbabe baadbabe baadbabe baadbabe ................


Current thread (0x0000000141824c10): WorkerThread "Shenandoah GC Threads#0" [id=12803, stack(0x000000016df08000,0x000000016e10b000) (2060K)]

Stack: [0x000000016df08000,0x000000016e10b000], sp=0x000000016e1085e0, free space=2049k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.dylib+0x13fcf14] VMError::report(outputStream*, bool)+0x1b58 (shenandoahMark.inline.hpp:69)
V [libjvm.dylib+0x1400884] VMError::report_and_die(int, char const*, char const*, char*, Thread*, unsigned char*, void const*, void const*, char const*, int, unsigned long)+0x55c
V [libjvm.dylib+0x6045bc] print_error_for_unit_test(char const*, char const*, char*)+0x0
V [libjvm.dylib+0x604540] report_vm_error(char const*, int, char const*, char const*, ...)+0x0
V [libjvm.dylib+0x10607c4] ShenandoahAsserts::print_failure(ShenandoahAsserts::SafeLevel, oop, void*, oop, char const*, char const*, char const*, int)+0x754
V [libjvm.dylib+0x106150c] ShenandoahAsserts::assert_correct(void*, oop, char const*, int)+0x970
V [libjvm.dylib+0x106236c] ShenandoahAsserts::assert_not_forwarded(void*, oop, char const*, int)+0x7c
V [libjvm.dylib+0x112af48] void ShenandoahMark::do_task<ShenandoahMarkRefsClosure<(ShenandoahGenerationType)1>, (ShenandoahGenerationType)1, (StringDedupMode)0>(Padded<BufferedOverflowTaskQueue<ShenandoahMarkTask, (MemTag)5, 131072u>, 128ul>*, ShenandoahMarkRefsClosure<(ShenandoahGenerationType)1>*, unsigned short*, StringDedup::Requests*, ShenandoahMarkTask*, unsigned int)+0xc4
V [libjvm.dylib+0x1129278] void ShenandoahMark::mark_loop_work<ShenandoahMarkRefsClosure<(ShenandoahGenerationType)1>, (ShenandoahGenerationType)1, true, (StringDedupMode)0>(ShenandoahMarkRefsClosure<(ShenandoahGenerationType)1>*, unsigned short*, unsigned int, TaskTerminator*, StringDedup::Requests*)+0x5f0
V [libjvm.dylib+0x1120038] void ShenandoahMark::mark_loop_prework<(ShenandoahGenerationType)1, true, (StringDedupMode)0>(unsigned int, TaskTerminator*, StringDedup::Requests*, bool)+0x1e0
V [libjvm.dylib+0x1096778] ShenandoahConcurrentMarkingTask<(ShenandoahGenerationType)1>::work(unsigned int)+0x128
V [libjvm.dylib+0x146fd58] WorkerThread::run()+0x9c
V [libjvm.dylib+0x133ca94] Thread::call_run()+0xdc
V [libjvm.dylib+0xef7084] thread_native_entry(Thread*)+0x138
C [libsystem_pthread.dylib+0x6f94] _pthread_start+0x88