Every few days, the test java/lang/management/MemoryMXBean/MemoryTestZGC.sh crashes on macOS.
It is macOS 10.14.4, and it is a virtualized machine running with VMWare hypervisor.

stdout contains :
runOne -XX:+UnlockExperimentalVMOptions -XX:+UseZGC MemoryTest 1 1
#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x000000010c63e00e, pid=70959, tid=7427
#
# JRE version: OpenJDK Runtime Environment (15.0.0.1) (build 15.0.0.1-internal+0-adhoc.openjdk.jdk)
# Java VM: OpenJDK 64-Bit Server VM (15.0.0.1-internal+0-adhoc.openjdk.jdk, mixed mode, tiered, z gc, bsd-amd64)
# Problematic frame:
# V [libjvm.dylib+0x7b000e] ZCPU::id_slow()+0x56
#
# Core dump will be written. Default location: ./core.70959
#
# An error report file with more information is saved as:
# /mymacworkdir/JTwork/java/lang/management/MemoryMXBean/MemoryTestZGC/hs_err_pid70959.log
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#

backtrace from hserr :

#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x000000010c63e00e, pid=70959, tid=7427
#
# JRE version: OpenJDK Runtime Environment (15.0.0.1) (build 15.0.0.1-internal+0-adhoc.openjdk.jdk)
# Java VM: OpenJDK 64-Bit Server VM (15.0.0.1-internal+0-adhoc.openjdk.jdk, mixed mode, tiered, z gc, bsd-amd64)
# Problematic frame:
# V [libjvm.dylib+0x7b000e] ZCPU::id_slow()+0x56
#
# Core dump will be written. Default location: ./core.70959
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#

--------------- S U M M A R Y ------------

Command Line: -Xmx768m -Djava.awt.headless=true -Djava.util.prefs.userRoot=/mydir/jtreg_jdk_java_lang_management_work/tmp -Djava.io.tmpdir=/mydir/jtreg_jdk_java_lang_management_work/tmp -Djdk.test.lib.artifacts.devkit-macosx_x64=/mydir2/devkit/Xcode9.2-MacOSX10.13-devkit -ea -esa -XX:+UnlockExperimentalVMOptions -XX:+UseZGC MemoryTest 1 1

Host: MacPro6,1 x86_64 3337 MHz, 12 cores, 16G, Darwin 18.5.0
Time: Tue Mar 24 23:14:32 2020 CET elapsed time: 0.213331 seconds (0d 0h 0m 0s)

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

Current thread (0x00007f9f81002600): JavaThread "main" [_thread_in_vm, id=7427, stack(0x0000700007f60000,0x0000700008060000)]

Stack: [0x0000700007f60000,0x0000700008060000], sp=0x000070000805ee30, free space=1019k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.dylib+0x7b000e] ZCPU::id_slow()+0x56
V [libjvm.dylib+0x7bdfb3] ZObjectAllocator::shared_small_page_addr() const+0x41
V [libjvm.dylib+0x7be871] ZObjectAllocator::remaining() const+0x9
V [libjvm.dylib+0x7b3403] ZHeap::unsafe_max_tlab_alloc() const+0xd
V [libjvm.dylib+0x55de8d] ThreadLocalAllocBuffer::compute_size(unsigned long)+0x33
V [libjvm.dylib+0x55dd82] MemAllocator::allocate_inside_tlab_slow(MemAllocator::Allocation&) const+0xca
V [libjvm.dylib+0x55df72] MemAllocator::mem_allocate(MemAllocator::Allocation&) const+0x24
V [libjvm.dylib+0x55dfd3] MemAllocator::allocate() const+0x47
V [libjvm.dylib+0x329368] InstanceKlass::allocate_instance(Thread*)+0x44
V [libjvm.dylib+0x16a0c2] Runtime1::new_instance(JavaThread*, Klass*)+0x84
v ~RuntimeStub::fast_new_instance Runtime1 stub
J 59 c1 java.util.HashMap.putVal(ILjava/lang/Object;Ljava/lang/Object;ZZ)Ljava/lang/Object; java.base@15.0.0.1-internal (300 bytes) @ 0x000000011a1d16e6 [0x000000011a1d06c0+0x0000000000001026]
J 66 c1 java.util.HashSet.add(Ljava/lang/Object;)Z java.base@15.0.0.1-internal (20 bytes) @ 0x000000011a1d3e34 [0x000000011a1d3be0+0x0000000000000254]
j java.util.AbstractCollection.addAll(Ljava/util/Collection;)Z+29 java.base@15.0.0.1-internal
j java.util.HashSet.<init>(Ljava/util/Collection;)V+35 java.base@15.0.0.1-internal
j java.util.Set.copyOf(Ljava/util/Collection;)Ljava/util/Set;+17 java.base@15.0.0.1-internal
j java.lang.ModuleLayer.modules()Ljava/util/Set;+19 java.base@15.0.0.1-internal
j jdk.internal.module.ModuleBootstrap.addIllegalAccess(Ljava/lang/module/ModuleFinder;Ljava/util/Map;Ljava/util/Map;Ljava/lang/ModuleLayer;Z)V+277 java.base@15.0.0.1-internal
j jdk.internal.module.ModuleBootstrap.boot()Ljava/lang/ModuleLayer;+1278 java.base@15.0.0.1-internal
j java.lang.System.initPhase2(ZZ)I+0 java.base@15.0.0.1-internal
v ~StubRoutines::call_stub
V [libjvm.dylib+0x33fd90] JavaCalls::call_helper(JavaValue*, methodHandle const&, JavaCallArguments*, Thread*)+0x256
V [libjvm.dylib+0x33f6e7] JavaCalls::call_static(JavaValue*, Klass*, Symbol*, Symbol*, JavaCallArguments*, Thread*)+0xbb
V [libjvm.dylib+0x72ffc1] Threads::create_vm(JavaVMInitArgs*, bool*)+0x66f
V [libjvm.dylib+0x38f10b] JNI_CreateJavaVM+0x60
C [libjli.dylib+0x3e2d] JavaMain+0x10b
C [libjli.dylib+0x6b2c] ThreadJavaMain+0x9
C [libsystem_pthread.dylib+0x32eb] _pthread_body+0x7e
C [libsystem_pthread.dylib+0x6249] _pthread_start+0x42
C [libsystem_pthread.dylib+0x240d] thread_start+0xd

Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
v ~RuntimeStub::fast_new_instance Runtime1 stub
J 59 c1 java.util.HashMap.putVal(ILjava/lang/Object;Ljava/lang/Object;ZZ)Ljava/lang/Object; java.base@15.0.0.1-internal (300 bytes) @ 0x000000011a1d16e6 [0x000000011a1d06c0+0x0000000000001026]
J 66 c1 java.util.HashSet.add(Ljava/lang/Object;)Z java.base@15.0.0.1-internal (20 bytes) @ 0x000000011a1d3e34 [0x000000011a1d3be0+0x0000000000000254]
j java.util.AbstractCollection.addAll(Ljava/util/Collection;)Z+29 java.base@15.0.0.1-internal
j java.util.HashSet.<init>(Ljava/util/Collection;)V+35 java.base@15.0.0.1-internal
j java.util.Set.copyOf(Ljava/util/Collection;)Ljava/util/Set;+17 java.base@15.0.0.1-internal
j java.lang.ModuleLayer.modules()Ljava/util/Set;+19 java.base@15.0.0.1-internal
j jdk.internal.module.ModuleBootstrap.addIllegalAccess(Ljava/lang/module/ModuleFinder;Ljava/util/Map;Ljava/util/Map;Ljava/lang/ModuleLayer;Z)V+277 java.base@15.0.0.1-internal
j jdk.internal.module.ModuleBootstrap.boot()Ljava/lang/ModuleLayer;+1278 java.base@15.0.0.1-internal
j java.lang.System.initPhase2(ZZ)I+0 java.base@15.0.0.1-internal
v ~StubRoutines::call_stub