The following test fails in the JDK16 CI:

vmTestbase/nsk/stress/stack/stack016.java

Here's a snippet from the log file:

#section:main
----------messages:(4/225)----------
command: main -Xss448K nsk.stress.stack.stack016 -eager
reason: User specified action: run main/othervm/timeout=900 -Xss448K nsk.stress.stack.stack016 -eager
Mode: othervm [/othervm specified]
elapsed time (seconds): 23.298
----------configuration:(0/0)----------
----------System.out:(4/170)----------
Maximal recursion depth: 2710
java.lang.Error: TEST_BUG: trickyRecursion() must throw an error anyway!
at nsk.stress.stack.stack016.run(stack016.java:187)
# TEST FAILED
----------System.err:(0/0)----------
----------rerun:(34/6960)*----------

There was a recent fix in this area:

    JDK-8251490 [TESTBUG] The Java thread stack size specified is
                           too small for nsk/stress/stack. Specify at least 448k

There is a follow-up to JDK-8251490, but that appears to be
related to timeouts in the tests after the switch to 448K:

    JDK-8252108 Modify nsk/stress/stack tests to check page size

This bug's failure mode is not a timeout.