The following testcase crashes on mozilla-central revision 71fd23fa0803 (build with --enable-debug --enable-more-deterministic, run with --fuzzing-safe --no-threads --no-baseline --no-ion): g = newGlobal(); g.parent = this; g.eval("(" + function() { Debugger(parent).onExceptionUnwind = function() 0; } + ")()"); async function f() { t; } f(); Backtrace: 0 js-dbg-64-dm-clang-darwin-71fd23fa0803 0x0000000108f06eaa JSContext::getPendingException(JS::MutableHandle<JS::Value>) + 282 (jscntxt.cpp:911) 1 js-dbg-64-dm-clang-darwin-71fd23fa0803 0x000000010917e7ae js::GetAndClearException(JSContext*, JS::MutableHandle<JS::Value>) + 14 (Interpreter.cpp:4431) 2 js-dbg-64-dm-clang-darwin-71fd23fa0803 0x0000000108b027af js::AsyncFunctionThrown(JSContext*, JS::Handle<js::PromiseObject*>) + 111 (Promise.cpp:2138) 3 js-dbg-64-dm-clang-darwin-71fd23fa0803 0x000000010904b214 AsyncFunctionResume(JSContext*, JS::Handle<js::PromiseObject*>, JS::Handle<JS::Value>, ResumeKind, JS::Handle<JS::Value>) + 404 (AsyncFunction.cpp:165) /snip For detailed crash information, see attachment.

autoBisect shows this is probably related to the following changeset: The first bad revision is: changeset: https://hg.mozilla.org/mozilla-central/rev/9ced693a9b87 user: Tooru Fujisawa date: Wed Nov 09 03:27:49 2016 +0900 summary: Bug 1314055 - Part 1: Port async/await implementation from self-hosted JS to C++. r=till Arai-san, is bug 1314055 a likely regressor?

Yes, thanks :) I needed the same code as AbruptRejectPromise, to detect the case that no pending exception.

Comment on attachment 8810610 [details] [diff] [review] Detect uncatchable exception in AsyncFunctionThrown. Review of attachment 8810610 [details] [diff] [review]: ----------------------------------------------------------------- Sorry, I should've caught this.

https://hg.mozilla.org/integration/mozilla-inbound/rev/be0a409b178acc10fc89b0d528c78a03755d89e4 Bug 1317460 - Detect uncatchable exception in AsyncFunctionThrown. r=till

Comment on attachment 8810610 [details] [diff] [review] Detect uncatchable exception in AsyncFunctionThrown. Approval Request Comment > [Feature/regressing bug #] Bug 1314055 > [User impact if declined] Possible crash while using debugger > [Describe test coverage new/current, TreeHerder] Tested on m-c > [Risks and why] Low, it falls back to normal failure path, instead of crashing. > [String/UUID change made/needed] None

Comment on attachment 8810610 [details] [diff] [review] Detect uncatchable exception in AsyncFunctionThrown. Fix recent regression, take in aurora