Hi, In Python 2, an exception has no __traceback__ attribute. Calling call_exception_handler() with the exception is not enough to get the traceback.
I propose to add new exc_info key to the context in Trollius. If exc_info is True, pass sys.exc_info() to the logger. Could you please review: http://codereview.appspot.com/68560043 By the way, it looks like there is no unit test checking that the exception handler logs a traceback. See also my issue proposing to log where a Future was created, it adds some tests on the traceback (but not directly related to call_exception_handler): http://code.google.com/p/tulip/issues/detail?id=137 https://codereview.appspot.com/64900043/ Victor
