连接现有Jupyter Notebook时QtConsole启动报错求助

现象 #

• 可正常启动独立Jupyter QtConsole：

  $ jupyter qtconsole
  

• 使用以下命令连接现有Notebook内核时，会弹出无法使用的空白QtConsole并报错：

  $ jupyter qtconsole --existing
  

  或指定内核文件：

  $ jupyter qtconsole --existing kernel-e73a6873-0080-4bd5-9433-3ekk5c52b5c3.json
  

报错信息 #

ERROR:tornado.general:Uncaught exception in ZMQStream callback
Traceback (most recent call last):
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 556, in _run_callback
    callback(*args, **kwargs)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/jupyter_client/threaded.py", line 121, in _handle_recv
    msg_list = self.ioloop._asyncio_event_loop.run_until_complete(get_msg(future_msg))
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/base_events.py", line 623, in run_until_complete
    self._check_running()
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/base_events.py", line 585, in _check_running
    raise RuntimeError(
RuntimeError: Cannot run the event loop while another loop is running
ERROR:tornado.general:Uncaught exception in zmqstream callback
Traceback (most recent call last):
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 577, in _handle_events
    self._handle_recv()
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 606, in _handle_recv
    self._run_callback(callback, msg)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 556, in _run_callback
    callback(*args, **kwargs)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/jupyter_client/threaded.py", line 121, in _handle_recv
    msg_list = self.ioloop._asyncio_event_loop.run_until_complete(get_msg(future_msg))
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/base_events.py", line 623, in run_until_complete
    self._check_running()
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/base_events.py", line 585, in _check_running
    raise RuntimeError(
RuntimeError: Cannot run the event loop while another loop is running
ERROR:asyncio:Exception in callback BaseAsyncIOLoop._handle_events(24, 1)
handle: <Handle BaseAsyncIOLoop._handle_events(24, 1)>
Traceback (most recent call last):
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/events.py", line 80, in _run
    self._context.run(self._callback, *self._args)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/tornado/platform/asyncio.py", line 189, in _handle_events
    handler_func(fileobj, events)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 577, in _handle_events
    self._handle_recv()
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 606, in _handle_recv
    self._run_callback(callback, msg)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 556, in _run_callback
    callback(*args, **kwargs)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/jupyter_client/threaded.py", line 121, in _handle_recv
    msg_list = self.ioloop._asyncio_event_loop.run_until_complete(get_msg(future_msg))
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/base_events.py", line 623, in run_until_complete
    self._check_running()
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/base_events.py", line 585, in _check_running
    raise RuntimeError(
RuntimeError: Cannot run the event loop while another loop is running
ERROR:tornado.general:Uncaught exception in ZMQStream callback
Traceback (most recent call last):
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 556, in _run_callback
    callback(*args, **kwargs)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/jupyter_client/threaded.py", line 121, in _handle_recv
    msg_list = self.ioloop._asyncio_event_loop.run_until_complete(get_msg(future_msg))
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/base_events.py", line 623, in run_until_complete
    self._check_running()
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/base_events.py", line 585, in _check_running
    raise RuntimeError(
RuntimeError: Cannot run the event loop while another loop is running
ERROR:tornado.general:Uncaught exception in zmqstream callback
Traceback (most recent call last):
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 577, in _handle_events
    self._handle_recv()
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 606, in _handle_recv
    self._run_callback(callback, msg)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 556, in _run_callback
    callback(*args, **kwargs)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/jupyter_client/threaded.py", line 121, in _handle_recv
    msg_list = self.ioloop._asyncio_event_loop.run_until_complete(get_msg(future_msg))
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/base_events.py", line 623, in run_until_complete
    self._check_running()
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/base_events.py", line 585, in _check_running
    raise RuntimeError(
RuntimeError: Cannot run the event loop while another loop is running
ERROR:asyncio:Exception in callback BaseAsyncIOLoop._handle_events(22, 1)
handle: <Handle BaseAsyncIOLoop._handle_events(22, 1)>
Traceback (most recent call last):
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/events.py", line 80, in _run
    self._context.run(self._callback, *self._args)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/tornado/platform/asyncio.py", line 189, in _handle_events
    handler_func(fileobj, events)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 577, in _handle_events
    self._handle_recv()
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 606, in _handle_recv
    self._run_callback(callback, msg)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/zmq/eventloop/zmqstream.py", line 556, in _run_callback
    callback(*args, **kwargs)
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages/jupyter_client/threaded.py", line 121, in _handle_recv
    msg_list = self.ioloop._asyncio_event_loop.run_until_complete(get_msg(future_msg))
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/base_events.py", line 623, in run_until_complete
    self._check_running()
  File "/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/asyncio/base_events.py", line 585, in _check_running
    raise RuntimeError(
RuntimeError: Cannot run the event loop while another loop is running
/home/bilgen/anaconda3/envs/ml_env/lib/python3.9/functools.py:834: RuntimeWarning: coroutine 'get_msg' was never awaited
  impl = registry[cls]
RuntimeWarning: Enable tracemalloc to get the object allocation traceback

环境信息 #

• Ubuntu版本：

  $ lsb_release -a
  

  No LSB modules are available.
  Distributor ID: Ubuntu
  Description: Ubuntu 20.04.4 LTS
  Release: 20.04
  Codename: focal

• Jupyter Notebook版本：

  $ pip show notebook
  

  Name: notebook
  Version: 6.4.12
  Summary: A web-based notebook environment for interactive computing
  Home-page: http://jupyter.org
  Author: Jupyter Development Team
  Author-email: jupyter@googlegroups.com
  License: BSD
  Location: /home/bilgen/anaconda3/envs/ml_env/lib/python3.9/site-packages
  Requires: argon2-cffi, ipykernel, ipython-genutils, jinja2, jupyter-client, jupyter-core, nbconvert, nbformat, nest-asyncio, prometheus-client, pyzmq, Send2Trash, terminado, tornado, traitlets
  Required-by:

• QtConsole版本：

  $ pip show qtconsole
  

  Name: qtconsole
  Version: 5.3.1
  Summary: Jupyter Qt console
  Home-page: http://jupyter.org
  Author: Jupyter Development Team
  Author-email: jupyter@googlegroups.com
  License: BSD
  Requires: ipykernel, ipython-genutils, jupyter-client, jupyter core, pygments, pyzmq, qtpy, traitlets
  Required-by:

解决方案 #

方案1：降级jupyter-client版本 #

该报错源于jupyter-client与QtConsole、Notebook的异步事件循环处理不兼容，尝试降级到7.4.9版本：

pip install jupyter-client==7.4.9

之后重新运行jupyter qtconsole --existing测试连接。

方案2：禁用nest-asyncio #

Notebook默认启用nest-asyncio允许嵌套事件循环，会与QtConsole的事件循环冲突：

1. 生成/打开Notebook配置文件：

   jupyter notebook --generate-config
   

2. 在配置文件中添加或修改：

   c.NotebookApp.use_nest_asyncio = False
   

3. 重启Notebook内核后再尝试连接。

方案3：临时替代方案 #

若上述方法无效，可使用ipython console连接现有内核：

ipython console --existing

内容的提问来源于stack exchange，提问作者ibilgen