Seen during tier7 testing, but there have been other occurrences:

Sending command: cont
reply[0]: > Set deferred watch modification of nsk.jdb.unwatch.unwatch002.unwatch002a$CheckedFields.FV1
reply[1]: Set deferred watch accesses of nsk.jdb.unwatch.unwatch002.unwatch002a$CheckedFields.FV1
reply[2]: Set deferred watch modification of nsk.jdb.unwatch.unwatch002.unwatch002a$CheckedFields.FT1
reply[3]: Set deferred watch accesses of nsk.jdb.unwatch.unwatch002.unwatch002a$CheckedFields.FT1
reply[4]:
reply[5]: Breakpoint hit: "thread=main", nsk.jdb.unwatch.unwatch002.unwatch002a.breakHere(), line=42 bci=0
reply[6]: 42 static void breakHere () {}
reply[7]:
reply[8]: main[1]
Sending command: cont
reply[0]: >
reply[1]: Field (nsk.jdb.unwatch.unwatch002.unwatch002a.FS1) is null, will be instance of java.lang.Boolean[1] (id=706):
Sending command: cont
# ERROR: Caught unexpected exception while executing the test: nsk.share.Failure: Prompt is not received during 300200 milliseconds.
The following stacktrace is for failure analysis.
nsk.share.TestFailure: Caught unexpected exception while executing the test: nsk.share.Failure: Prompt is not received during 300200 milliseconds.
at nsk.share.Log.logExceptionForFailureAnalysis(Log.java:428)
at nsk.share.Log.complain(Log.java:399)
at nsk.share.jdb.JdbTest.failure(JdbTest.java:74)
at nsk.share.jdb.JdbTest.runTest(JdbTest.java:158)
at nsk.jdb.unwatch.unwatch002.unwatch002.run(unwatch002.java:85)
at nsk.jdb.unwatch.unwatch002.unwatch002.main(unwatch002.java:78)
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:566)
at PropertyResolvingWrapper.main(PropertyResolvingWrapper.java:104)
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:566)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:115)
at java.base/java.lang.Thread.run(Thread.java:834)
nsk.share.Failure: Prompt is not received during 300200 milliseconds.
at nsk.share.jdb.Jdb.waitForPrompt(Jdb.java:496)
at nsk.share.jdb.Jdb.receiveReply(Jdb.java:403)
at nsk.share.jdb.Jdb.receiveReplyFor(Jdb.java:351)
at nsk.share.jdb.Jdb.receiveReplyFor(Jdb.java:333)
at nsk.share.jdb.Jdb.receiveReplyFor(Jdb.java:322)
at nsk.jdb.unwatch.unwatch002.unwatch002.runCases(unwatch002.java:116)
at nsk.share.jdb.JdbTest.runTest(JdbTest.java:149)
at nsk.jdb.unwatch.unwatch002.unwatch002.run(unwatch002.java:85)
at nsk.jdb.unwatch.unwatch002.unwatch002.main(unwatch002.java:78)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at PropertyResolvingWrapper.main(PropertyResolvingWrapper.java:104)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:115)
at java.base/java.lang.Thread.run(Thread.java:834)