com/sun/jdi/ProcessAttachTest.java fails intermittently: Remote thread failed for unknown reason

  com/sun/jdi/ProcessAttachTest.java fails intermittently:

----------System.err:(19/1329)----------
java.lang.InternalError: Remote thread failed for unknown reason
at jdk.attach/sun.tools.attach.VirtualMachineImpl.enqueue(Native Method)
at jdk.attach/sun.tools.attach.VirtualMachineImpl.execute(VirtualMachineImpl.java:96)
at jdk.attach/sun.tools.attach.HotSpotVirtualMachine.executeCommand(HotSpotVirtualMachine.java:309)
at jdk.attach/sun.tools.attach.HotSpotVirtualMachine.getAgentProperties(HotSpotVirtualMachine.java:202)
at jdk.jdi/com.sun.tools.jdi.ProcessAttachingConnector.attach(ProcessAttachingConnector.java:103)
at ProcessAttachTest.tryDebug(ProcessAttachTest.java:107)
at ProcessAttachTest.runTest(ProcessAttachTest.java:87)
at ProcessAttachTest.main(ProcessAttachTest.java:66)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
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$SameVMRunnable.run(MainActionHelper.java:229)
at java.base/java.lang.Thread.run(Thread.java:842)

JavaTest Message: Test threw exception: java.lang.InternalError
JavaTest Message: shutting down test

result: Failed. Execution failed: `main' threw exception: java.lang.InternalError: Remote thread failed for unknown reason