Kernel Error in Jupyter Notebook - _kernel_spec_manager_changed() takes 1 positional argument but 2 were given

Notebook
1

How to solve “_kernel_spec_manager_changed() takes 1 positional argument but 2 were given”? Uninstall and reinstall tornado again doesn’t help.

Error:
Traceback (most recent call last):
File “/usr/local/lib/python3.9/site-packages/tornado/web.py”, line 1704, in _execute
result = await result
File “/usr/local/lib/python3.9/site-packages/tornado/gen.py”, line 769, in run
yielded = self.gen.throw(*exc_info) # type: ignore
File “/usr/local/lib/python3.9/site-packages/notebook/services/sessions/handlers.py”, line 69, in post
model = yield maybe_future(
File “/usr/local/lib/python3.9/site-packages/tornado/gen.py”, line 762, in run
value = future.result()
File “/usr/local/lib/python3.9/site-packages/tornado/gen.py”, line 769, in run
yielded = self.gen.throw(*exc_info) # type: ignore
File “/usr/local/lib/python3.9/site-packages/notebook/services/sessions/sessionmanager.py”, line 88, in create_session
kernel_id = yield self.start_kernel_for_session(session_id, path, name, type, kernel_name)
File “/usr/local/lib/python3.9/site-packages/tornado/gen.py”, line 762, in run
value = future.result()
File “/usr/local/lib/python3.9/site-packages/tornado/gen.py”, line 769, in run
yielded = self.gen.throw(*exc_info) # type: ignore
File “/usr/local/lib/python3.9/site-packages/notebook/services/sessions/sessionmanager.py”, line 100, in start_kernel_for_session
kernel_id = yield maybe_future(
File “/usr/local/lib/python3.9/site-packages/tornado/gen.py”, line 762, in run
value = future.result()
File “/usr/local/lib/python3.9/site-packages/notebook/services/kernels/kernelmanager.py”, line 176, in start_kernel
kernel_id = await maybe_future(self.pinned_superclass.start_kernel(self, **kwargs))
File “/usr/local/lib/python3.9/site-packages/jupyter_client/multikernelmanager.py”, line 184, in start_kernel
km, kernel_name, kernel_id = self.pre_start_kernel(kernel_name, kwargs)
File “/usr/local/lib/python3.9/site-packages/jupyter_client/multikernelmanager.py”, line 169, in pre_start_kernel
km = self.kernel_manager_factory(connection_file=os.path.join(
File “/usr/local/lib/python3.9/site-packages/jupyter_client/multikernelmanager.py”, line 83, in create_kernel_manager
km = kernel_manager_ctor(*args, **kwargs)
File “/usr/local/lib/python3.9/site-packages/traitlets/config/configurable.py”, line 82, in init
super(Configurable, self).init(**kwargs)
File “/usr/local/lib/python3.9/site-packages/traitlets/traitlets.py”, line 1080, in init
super_kwargs[key] = value
File “/usr/local/Cellar/python@3.9/3.9.2_1/Frameworks/Python.framework/Versions/3.9/lib/python3.9/contextlib.py”, line 124, in exit
next(self.gen)
File “/usr/local/lib/python3.9/site-packages/traitlets/traitlets.py”, line 1214, in hold_trait_notifications
self.notify_change(change)
File “/usr/local/lib/python3.9/site-packages/traitlets/traitlets.py”, line 1227, in notify_change
return self._notify_observers(change)
File “/usr/local/lib/python3.9/site-packages/traitlets/traitlets.py”, line 1264, in _notify_observers
c(event)
File “/usr/local/lib/python3.9/site-packages/traitlets/traitlets.py”, line 888, in compatible_observer
return func(self, change)
TypeError: _kernel_spec_manager_changed() takes 1 positional argument but 2 were given

Available kernels:
julia-1.5 /Users/mer/Library/Jupyter/kernels/julia-1.5
python2 /Users/mer/Library/Jupyter/kernels/python2
python3 /usr/local/share/jupyter/kernels/python3

2

Hi @pdflu. This issue has been addressed in jupyter_client >= 6.1.10 per this pull request. Please update your jupyter_client package and you should be moving forward again.

2 Likes
3

I experience the same issue with jupyter_client = 8.5.0 when trying to launch from a virtual environment. I get a pop up window “Error starting kernel”.

The virtual environment seems to have all the packages properly install with pip from the activated environment. Launching Jupyter with the activated environment but also directly from the environment as .env_p10/bin/jupyter lab.