Method _call_task_errbacks

celery/backends/base.py:244–288

(self, request, exc, traceback)

                self._call_task_errbacks(request, exc, traceback)

    def _call_task_errbacks(self, request, exc, traceback):
        old_signature = []
        for errback in request.errbacks:
            errback = self.app.signature(errback)
            if not errback._app:
                # Ensure all signatures have an application
                errback._app = self.app
            try:
                if (
                        # Celery tasks type created with the @task decorator have
                        # the __header__ property, but Celery task created from
                        # Task class do not have this property.
                        # That's why we have to check if this property exists
                        # before checking is it partial function.
                        hasattr(errback.type, '__header__') and

                        # workaround to support tasks with bind=True executed as
                        # link errors. Otherwise, retries can't be used
                        not isinstance(errback.type.__header__, partial) and
                        arity_greater(errback.type.__header__, 1)
                ):
                    errback(request, exc, traceback)
                else:
                    old_signature.append(errback)
            except NotRegistered:
                # Task may not be present in this worker.
                # We simply send it forward for another worker to consume.
                # If the task is not registered there, the worker will raise
                # NotRegistered.
                old_signature.append(errback)

        if old_signature:
            # Previously errback was called as a task so we still
            # need to do so if the errback only takes a single task_id arg.
            task_id = request.id
            root_id = request.root_id or task_id
            g = group(old_signature, app=self.app)
            if self.app.conf.task_always_eager or request.delivery_info.get('is_eager', False):
                g.apply(
                    (task_id,), parent_id=task_id, root_id=root_id
                )
            else:
                g.apply_async(
                    (task_id,), parent_id=task_id, root_id=root_id
                )

    def mark_as_revoked(self, task_id, reason='',
                        request=None, store_result=True, state=states.REVOKED):