python/cpython · error · RuntimeError

Runner is closed

Error message

Runner is closed

What it means

Error "Runner is closed" thrown in python/cpython.

Source

Thrown at Lib/asyncio/runners.py:143

        self._interrupt_count = 0
        try:
            return self._loop.run_until_complete(task)
        except exceptions.CancelledError:
            if self._interrupt_count > 0:
                uncancel = getattr(task, "uncancel", None)
                if uncancel is not None and uncancel() == 0:
                    raise KeyboardInterrupt()
            raise  # CancelledError
        finally:
            if (sigint_handler is not None
                and signal.getsignal(signal.SIGINT) is sigint_handler
            ):
                signal.signal(signal.SIGINT, signal.default_int_handler)

    def _lazy_init(self):
        if self._state is _State.CLOSED:
            raise RuntimeError("Runner is closed")
        if self._state is _State.INITIALIZED:
            return
        if self._loop_factory is None:
            self._loop = events.new_event_loop()
            if not self._set_event_loop:
                # Call set_event_loop only once to avoid calling
                # attach_loop multiple times on child watchers
                events.set_event_loop(self._loop)
                self._set_event_loop = True
        else:
            self._loop = self._loop_factory()
        if self._debug is not None:
            self._loop.set_debug(self._debug)
        self._context = contextvars.copy_context()
        self._state = _State.INITIALIZED

    def _on_sigint(self, signum, frame, main_task):
        self._interrupt_count += 1

View on GitHub (pinned to bc6749cc3b)

Solutions

1. Do not use the Runner after calling runner.close(); create a new asyncio.Runner() for further runs.

When it happens

Trigger: Raised when an operation is attempted on a Runner that has been closed.

Common situations: See trigger scenarios.

AI-assisted analysis of python/cpython@bc6749cc3b (2026-08-14). Data as JSON: /api/errors/0a963c06a4688eae. Report an issue: GitHub.