Steps to reproduce: run the following JS code: function step(count) { if (count == 0) { console.trace(); } else if (count % 2 == 0) { step(count - 1); } else { Promise.resolve(count - 1).then(step); } } step(3); Expected result: console.trace() reports all stack frames, i.e., alternating sync/async calls to step(): step() (Async: promise resolver) step() step() (Async: promise resolver) step() Actual result: The sync frames between the two async's are missing: step() (Async: promise resolver) step() (Async: promise resolver) step() This seems to happen only for promises: if I use setTimeout instead: setTimeout(() => step.bind(null, count - 1), 0); // replace the Promise.resolve call with this Then there is a step() frame between the two (Async: setTimeout handler) ones.

This looks fixed to me. I'm not sure how the fix was introduced though