Seems to be a new failure mode:

----------System.err:(36/2448)----------
sun.jvm.hotspot.oops.UnknownOopException
at jdk.hotspot.agent/sun.jvm.hotspot.oops.ObjectHeap.newOop(ObjectHeap.java:193)
at jdk.hotspot.agent/sun.jvm.hotspot.oops.VMOopHandle.resolve(VMOopHandle.java:61)
at jdk.hotspot.agent/sun.jvm.hotspot.oops.Klass.getJavaMirror(Klass.java:114)
at jdk.hotspot.agent/sun.jvm.hotspot.utilities.HeapHprofBinWriter$4.visit(HeapHprofBinWriter.java:1120)
at jdk.hotspot.agent/sun.jvm.hotspot.classfile.ClassLoaderData.classesDo(ClassLoaderData.java:114)
at jdk.hotspot.agent/sun.jvm.hotspot.classfile.ClassLoaderDataGraph.classesDo(ClassLoaderDataGraph.java:84)
at jdk.hotspot.agent/sun.jvm.hotspot.utilities.HeapHprofBinWriter.writeClasses(HeapHprofBinWriter.java:1117)
at jdk.hotspot.agent/sun.jvm.hotspot.utilities.HeapHprofBinWriter.write(HeapHprofBinWriter.java:436)
at jdk.hotspot.agent/sun.jvm.hotspot.tools.JMap.writeHeapHprofBin(JMap.java:182)
at jdk.hotspot.agent/sun.jvm.hotspot.tools.JMap.run(JMap.java:97)
at jdk.hotspot.agent/sun.jvm.hotspot.tools.Tool.startInternal(Tool.java:262)
at jdk.hotspot.agent/sun.jvm.hotspot.tools.Tool.start(Tool.java:225)
at jdk.hotspot.agent/sun.jvm.hotspot.tools.Tool.execute(Tool.java:118)
at jdk.hotspot.agent/sun.jvm.hotspot.tools.JMap.main(JMap.java:176)
at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.runJMAP(SALauncher.java:331)
at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.main(SALauncher.java:483)

java.io.EOFException
at java.base/java.io.DataInputStream.readInt(DataInputStream.java:396)
at jdk.test.lib.hprof.parser.HprofReader.read(HprofReader.java:209)
at jdk.test.lib.hprof.parser.Reader.readFile(Reader.java:92)
at jdk.test.lib.hprof.HprofParser.parse(HprofParser.java:85)
at jdk.test.lib.hprof.HprofParser.parse(HprofParser.java:54)
at TestJmapCore.test(TestJmapCore.java:106)
at TestJmapCore.main(TestJmapCore.java:70)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:298)
at java.base/java.lang.Thread.run(Thread.java:832)

JavaTest Message: Test threw exception: java.io.EOFException