broken on python3.14 ('asyncio' has no attribute 'get_child_watcher')

[zokrezyl]

Hi,

unfortunatelly pynvim seems to be broken on 3.14

Traceback (most recent call last):
  File "/Users/user/work/my/ylib/sandbox/py/nvim/t.py", line 2, in <module>
    nvim = pynvim.attach('child', argv=["/usr/bin/env", "nvim", "--embed", "--headless"])
  File "/Users/user/.local/venv/python3.14/lib/python3.14/site-packages/pynvim/__init__.py", line 144, in attach
    child_session(cast(List[str], argv)) if session_type == 'child' else
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/user/.local/venv/python3.14/lib/python3.14/site-packages/pynvim/msgpack_rpc/__init__.py", line 49, in child_session
    return session('child', argv)
  File "/Users/user/.local/venv/python3.14/lib/python3.14/site-packages/pynvim/msgpack_rpc/__init__.py", line 23, in session
    loop = EventLoop(transport_type, *args, **kwargs)
  File "/Users/user/.local/venv/python3.14/lib/python3.14/site-packages/pynvim/msgpack_rpc/event_loop/asyncio.py", line 132, in __init__
    super().__init__(transport_type, *args, **kwargs)
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/user/.local/venv/python3.14/lib/python3.14/site-packages/pynvim/msgpack_rpc/event_loop/base.py", line 109, in __init__
    raise e
  File "/Users/user/.local/venv/python3.14/lib/python3.14/site-packages/pynvim/msgpack_rpc/event_loop/base.py", line 106, in __init__
    getattr(self, '_connect_{}'.format(transport_type))(*args, **kwargs)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/Users/user/.local/venv/python3.14/lib/python3.14/site-packages/pynvim/msgpack_rpc/event_loop/asyncio.py", line 201, in _connect_child
    self._child_watcher = asyncio.get_child_watcher()
                          ^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'asyncio' has no attribute 'get_child_watcher'

[justinmk]

Thanks for reporting. Looks like get_child_watcher is deprecated since python 3.12: https://docs.python.org/3/library/asyncio-policy.html#asyncio.AbstractEventLoopPolicy.get_child_watcher

An alternative isn't mentioned...

[cryptomilk]

I have a fix for that.