Test: jdk/jfr/startupargs/TestStartRecording.java
Observer on: MAC OSX so far, only once so far
Error type: assert/crash

Details:
#  assert(((((klass)->trace_id() & (JfrTraceIdEpoch::method_and_class_in_use_this_epoch_bits())) == (JfrTraceIdEpoch::method_and_class_in_use_this_epoch_bits())) != 0)) failed: invariant
#
# JRE version: Java(TM) SE Runtime Environment (13.0) (fastdebug build 13-internal+0-jdk13-jdk.241)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 13-internal+0-jdk13-jdk.241, mixed mode, sharing, tiered, compressed oops, g1 gc, bsd-amd64)


===================================
The file and line info point to: 
   jfrTraceId.inline.hpp:   assert(METHOD_AND_CLASS_USED_THIS_EPOCH(klass), "invariant");


inline traceid JfrTraceId::use(const Method* method, bool leakp /* false */) {
  assert(method != NULL, "invariant");
  SET_METHOD_FLAG_USED_THIS_EPOCH(method);
  const Klass* const klass = method->method_holder();
  assert(klass != NULL, "invariant");
  if (leakp) {
    SET_LEAKP_USED_THIS_EPOCH(klass);
    assert(LEAKP_USED_THIS_EPOCH(klass), "invariant");
  }
  SET_METHOD_AND_CLASS_USED_THIS_EPOCH(klass);
  assert(METHOD_AND_CLASS_USED_THIS_EPOCH(klass), "invariant");       <<<============
  return (METHOD_ID(klass, method));
}