Diagnosis when sub-JVM process fails catastrophically

[Martin Buchholz]

If an inferior java process fails while running tests, jtreg is often
unhelpful.  E.g. we might get SocketTimeoutException, or if the test itself
spawns a sub-process we might get Exit Code 139, with no more details.  But
there's a good chance that there's diagnostic information provided, perhaps
in an hs_errpid file.  Maybe those files should be looked for.  Maybe we
should invoke java with a flag like -XX:ErrorFile:/dev/stderr.  Maybe we
should be fixing jtreg itself (when spawning "other" VM or agent VMs) and
also JDK's own test library's helpers that spawn subprocesses.  At Google,
we see a background noise of failing tests that go undiagnosed, and
Oracle's tests seem to have the same problem.