RuntimeError: There is no current event loop in thread 'Thread-1 (thread_inner)'.

[alijaafar21]

Hello,

While attempting to invoke a deployed Modal function in a Chainlit application I faced the following error:

RuntimeError: There is no current event loop in thread 'Thread-1 (thread_inner)'.

This is how I am getting and invoking the function:

query_mistral_7b_instruct_v0p2 = modal.Function.from_name(app_name='...', tag='query_mistral_7b_instruct_v0p2')
response = query_mistral_7b_instruct_v0p2.remote('What is the meaning of a word?')

Kindly note that the same error was first happening when getting the function through modal.Function.lookup( )
but using modal.Function.from_name( ) made it work.
But now the .remote( ) is causing the same issue.

Here's the full stack trace:

Exception in thread Thread-1 (thread_inner):
Traceback (most recent call last):
  File "...\Python\Python312\Lib\threading.py", line 1073, in _bootstrap_inner
    self.run()
  File "...\Python\Python312\Lib\threading.py", line 1010, in run
    self._target(*self._args, **self._kwargs)
  File "...\venv\Lib\site-packages\synchronicity\synchronizer.py", line 168, in thread_inner        
    raise exc
  File "...\venv\Lib\site-packages\synchronicity\synchronizer.py", line 162, in thread_inner        
    asyncio.run(loop_inner())
  File "...\venv\Lib\site-packages\nest_asyncio.py", line 26, in run
    loop = asyncio.get_event_loop()
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "...\venv\Lib\site-packages\nest_asyncio.py", line 40, in _get_event_loop
    loop = events.get_event_loop_policy().get_event_loop()
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "...\Python\Python312\Lib\asyncio\events.py", line 702, in get_event_loop
    raise RuntimeError('There is no current event loop in thread %r.'
RuntimeError: There is no current event loop in thread 'Thread-1 (thread_inner)'.

• Python version: 3.12.2
• Modal Client version: 0.61.31

[alijaafar21]

Update:

After some searching, I came across the following PR that fixes a similar issue RuntimeError on nest_asyncio.apply() (There is no current event loop in thread 'Thread-3' ) by adding the following:

import asyncio, nest_asyncio

try:
    asyncio.get_event_loop()
    nest_asyncio.apply()
except RuntimeError:
    pass

Indeed, putting this code snippet in the same file that contains the invocation of the Modal function fixed the problem!

Thank you @eugeniashurko !

[mwaskom]

Hey @alijaafar21 just so I understand — is nest_asyncio a library you're using in your codebase? Any chance you have a minimal reproducer we could run to understand the underlying issue?

[alijaafar21]

Hello,

I am not directly using nest_asyncio in my code. But, I am working on a Chainlit app, which perhaps uses it.

I have created the following repo which will allow reproducing the error reported above by executing

chainlit run app.py

In app.py, I am trying to lookup a function and then invoke it.

Kindly note that if the try-except block in app.py is uncommented, the error no longer happens.

[mwaskom]

Thank you! I suspect that the issue is with the code underlying the philosophy-question-answerer app though and it's going to be hard to debug that without knowing what it looks like. Definitely would be easier for us to resolve this if we had a simple example we could run on our end to observe the error, although I appreciate that that may be difficult to produce.

[alijaafar21]

Kindly find the code of the function query_mistral_7b_instruct_v0p2 we are attempting to invoke here.