The following tests failed in the JDK16 CI:

sun/tools/jhsdb/JShellHeapDumpTest.java
sun/tools/jhsdb/HeapDumpTestWithActiveProcess.java
sun/tools/jhsdb/HeapDumpTest.java
sun/tools/jhsdb/BasicLauncherTest.java

Here's a snippet from the JShellHeapDumpTest.java log file:

#section:main
----------messages:(5/259)----------
command: main JShellHeapDumpTest
reason: User specified action: run main/timeout=240 JShellHeapDumpTest
Mode: othervm [test needs --add-modules]
Additional options from @modules: --add-modules jdk.hotspot.agent,java.management
elapsed time (seconds): 69.832
----------configuration:(3/61)----------
Boot Layer
  add modules: jdk.hotspot.agent java.management

----------System.out:(45/2819)----------
Target JDK is not signed.
Starting Jshell
[JShell]:/System/Volumes/Data/mesos/work_dir/jib-master/install/jdk-16+3-50/macosx-x64-debug.jdk/jdk-16/fastdebug/bin/jshell
[JShell] | Welcome to JShell -- Version 16-ea
[JShell] | For an introduction type: /help intro
Jshell Started in 3092ms
Starting jmap against 36753
Adding 'sudo -E -n' to the command.
[2020-06-24T05:12:11.327967Z] Gathering output for process 36766
[2020-06-24T05:12:19.069322Z] Waiting for completion for process 36766
[2020-06-24T05:12:19.069488Z] Waiting for completion finished for process 36766
Output and diagnostic info for process 36766 was saved into 'pid-36766-output.log'
jhsdb jmap stdout:
Attaching to process ID 36753, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 16-ea+3-50

jhsdb jmap stderr:
java.lang.RuntimeException: Unable to deduce type of thread from address 0x00007fd05b809020 (expected type JavaThread, CompilerThread, ServiceThread, JvmtiAgentThread or CodeCacheSweeperThread)
at jdk.hotspot.agent/sun.jvm.hotspot.runtime.Threads.createJavaThreadWrapper(Threads.java:187)
at jdk.hotspot.agent/sun.jvm.hotspot.runtime.Threads.getJavaThreadAt(Threads.java:169)
at jdk.hotspot.agent/sun.jvm.hotspot.utilities.HeapHprofBinWriter.dumpStackTraces(HeapHprofBinWriter.java:712)
at jdk.hotspot.agent/sun.jvm.hotspot.utilities.HeapHprofBinWriter.write(HeapHprofBinWriter.java:439)
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)
Caused by: sun.jvm.hotspot.types.WrongTypeException: No suitable match for type of address 0x00007fd05b809020
at jdk.hotspot.agent/sun.jvm.hotspot.runtime.InstanceConstructor.newWrongTypeException(InstanceConstructor.java:62)
at jdk.hotspot.agent/sun.jvm.hotspot.runtime.VirtualConstructor.instantiateWrapperFor(VirtualConstructor.java:80)
at jdk.hotspot.agent/sun.jvm.hotspot.runtime.Threads.createJavaThreadWrapper(Threads.java:183)
... 11 more

###### End of all output:
[2020-06-24T05:12:19.090086Z] Waiting for completion for process 36766
[2020-06-24T05:12:19.090194Z] Waiting for completion finished for process 36766
[2020-06-24T05:12:19.090318Z] Waiting for completion for process 36766
[2020-06-24T05:12:19.090401Z] Waiting for completion finished for process 36766
Destroying jshell
Jshell destroyed
----------System.err:(49/3186)----------

JShellHeapDumpTest.java, HeapDumpTestWithActiveProcess.java and
HeapDumpTest.java fail in a similar way.


BasicLauncherTest.java fails a little differently:

----------System.err:(55/3405)----------
Attaching to process 36601, please wait...
Unable to connect to process ID 36601:

Doesn't appear to be a HotSpot VM (could not find symbol
"gHotSpotVMStructEntryTypeNameOffset" in remote process)
sun.jvm.hotspot.debugger.DebuggerException: Doesn't appear to be a HotSpot VM (could not find symbol "gHotSpotVMStructEntryTypeNameOffset" in remote process)
at jdk.hotspot.agent/sun.jvm.hotspot.HotSpotAgent.setupVM(HotSpotAgent.java:431)
at jdk.hotspot.agent/sun.jvm.hotspot.HotSpotAgent.go(HotSpotAgent.java:330)
at jdk.hotspot.agent/sun.jvm.hotspot.HotSpotAgent.attach(HotSpotAgent.java:139)
at jdk.hotspot.agent/sun.jvm.hotspot.CLHSDB.attachDebugger(CLHSDB.java:180)
at jdk.hotspot.agent/sun.jvm.hotspot.CLHSDB.run(CLHSDB.java:61)
at jdk.hotspot.agent/sun.jvm.hotspot.CLHSDB.main(CLHSDB.java:40)
at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.runCLHSDB(SALauncher.java:280)
at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.main(SALauncher.java:483)
finding class loader instances ..done.
computing per loader stat ..done.
please wait.. computing liveness..done.
Error attaching to process: Doesn't appear to be a HotSpot VM (could not find symbol "gHotSpotVMStructEntryTypeNameOffset" in remote process)
sun.jvm.hotspot.debugger.DebuggerException: Doesn't appear to be a HotSpot VM (could not find symbol "gHotSpotVMStructEntryTypeNameOffset" in remote process)
at jdk.hotspot.agent/sun.jvm.hotspot.HotSpotAgent.setupVM(HotSpotAgent.java:431)
at jdk.hotspot.agent/sun.jvm.hotspot.HotSpotAgent.go(HotSpotAgent.java:330)
at jdk.hotspot.agent/sun.jvm.hotspot.HotSpotAgent.attach(HotSpotAgent.java:139)
at jdk.hotspot.agent/sun.jvm.hotspot.tools.Tool.start(Tool.java:187)
at jdk.hotspot.agent/sun.jvm.hotspot.tools.Tool.execute(Tool.java:118)
at jdk.hotspot.agent/sun.jvm.hotspot.tools.JSnap.main(JSnap.java:87)
at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.runJSNAP(SALauncher.java:352)
at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.main(SALauncher.java:483)

 stdout: [Attaching to process ID 36660, please wait...
];
 stderr: []
 exitValue = 1

java.lang.RuntimeException: Test ERROR java.lang.RuntimeException: 'java.threads' missing from stdout/stderr

at BasicLauncherTest.launch(BasicLauncherTest.java:180)
at BasicLauncherTest.launch(BasicLauncherTest.java:190)
at BasicLauncherTest.main(BasicLauncherTest.java:204)
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.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:832)
Caused by: java.lang.RuntimeException: 'java.threads' missing from stdout/stderr

at jdk.test.lib.process.OutputAnalyzer.shouldContain(OutputAnalyzer.java:189)
at BasicLauncherTest.launch(BasicLauncherTest.java:175)
... 8 more

JavaTest Message: Test threw exception: java.lang.RuntimeException: Test ERROR java.lang.RuntimeException: 'java.threads' missing from stdout/stderr

JavaTest Message: shutting down test

STATUS:Failed.`main' threw exception: java.lang.RuntimeException: Test ERROR java.lang.RuntimeException: 'java.threads' missing from stdout/stderr
----------rerun:(39/6214)*----------