RuntimeError: no running event loop on version 3.0.37

My app (jellex) is getting the following traceback when starting on prompt-toolkit version 3.0.37. Previous versions of prompt-toolkit seem to work fine.

Traceback (most recent call last):
  File "/Users/kbrazil/.pyenv/versions/3.11.1/bin/jellex", line 5, in <module>
    from jellex.cli import main
  File "/Users/kbrazil/.pyenv/versions/3.11.1/lib/python3.11/site-packages/jellex/cli.py", line 231, in <module>
    query.insert_text('_')
  File "/Users/kbrazil/.pyenv/versions/3.11.1/lib/python3.11/site-packages/prompt_toolkit/buffer.py", line 1269, in insert_text
    get_app().create_background_task(self._async_completer())
  File "/Users/kbrazil/.pyenv/versions/3.11.1/lib/python3.11/site-packages/prompt_toolkit/application/application.py", line 1057, in create_background_task
    loop = self.loop or get_running_loop()
                        ^^^^^^^^^^^^^^^^^^
RuntimeError: no running event loop
sys:1: RuntimeWarning: coroutine 'Buffer._create_completer_coroutine.<locals>.async_completer' was never awaited

Reproduce the startup failure in jellex with prompt-toolkit 3.0.37, then inspect prompt_toolkit/buffer.py and prompt_toolkit/application/application.py at the traceback locations. Compare behavior with a working prompt-toolkit version; done means the application starts without the event-loop error or unawaited-coroutine warning.