- mozjs::jsapi::CapturedJSStack::as_string() (https://doc.servo.org/mozjs/rust/struct.CapturedJSStack.html#method.as_string) was updated to accept a second parameter which specifies which Stacktrace format to use. The default has been specified to preserve the (presumably) original behavior. - The related code has also been placed in an unsafe block since the capture_stack macro calling the unsafe mozjs::jsapi::CapturedJSStack::new() function. Seems that this commit (0703a1a) forgot this part.