Dear Matthias Klose,

trying to restart and run a jupyter python notebook kernel fails and I see the
following traceback:

[E 13:01:45.847 NotebookApp] Timeout should be used inside a task
     Traceback (most recent call last):
       File "/usr/lib/python3/dist-packages/jupyter_client/manager.py", line 88,
in wrapper
         out = await method(self, *args, **kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
       File "/usr/lib/python3/dist-packages/jupyter_client/manager.py", line
557, in _async_shutdown_kernel
         await self._async_finish_shutdown(restart=restart)
       File "/usr/lib/python3/dist-packages/jupyter_client/manager.py", line
480, in _async_finish_shutdown
         await asyncio.wait_for(
             self._async_wait(pollinterval=pollinterval), timeout=waittime / 2
         )
       File "/usr/lib/python3.14/asyncio/tasks.py", line 487, in wait_for
         async with timeouts.timeout(timeout):
                    ~~~~~~~~~~~~~~~~^^^^^^^^^
       File "/usr/lib/python3.14/asyncio/timeouts.py", line 89, in __aenter__
         raise RuntimeError("Timeout should be used inside a task")
     RuntimeError: Timeout should be used inside a task
[E 13:01:45.852 NotebookApp] Exception restarting kernel
     Traceback (most recent call last):
       File
"/usr/lib/python3/dist-packages/notebook/services/kernels/handlers.py", line 89,
in post
         yield maybe_future(km.restart_kernel(kernel_id))
       File "/usr/lib/python3/dist-packages/tornado/gen.py", line 783, in run
         value = future.result()
       File "/usr/lib/python3.14/asyncio/futures.py", line 208, in result
         raise self._exception.with_traceback(self._exception_tb)
       File "/usr/lib/python3.14/asyncio/tasks.py", line 289, in
__step_run_and_handle_result
         result = coro.send(None)
       File
"/usr/lib/python3/dist-packages/notebook/services/kernels/kernelmanager.py",
line 314, in restart_kernel
         await maybe_future(self.pinned_superclass.restart_kernel(self,
kernel_id, now=now))

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
       File "/usr/lib/python3/dist-packages/jupyter_core/utils/__init__.py",
line 171, in wrapped
         return _runner_map[name].run(inner)
                ~~~~~~~~~~~~~~~~~~~~~^^^^^^^
       File "/usr/lib/python3/dist-packages/jupyter_core/utils/__init__.py",
line 128, in run
         return fut.result(None)
                ~~~~~~~~~~^^^^^^
       File "/usr/lib/python3.14/concurrent/futures/_base.py", line 454, in result
         return self.__get_result()
                ~~~~~~~~~~~~~~~~~^^
       File "/usr/lib/python3.14/concurrent/futures/_base.py", line 396, in
__get_result
         raise self._exception
       File "/usr/lib/python3.14/asyncio/tasks.py", line 289, in
__step_run_and_handle_result
         result = coro.send(None)
       File
"/usr/lib/python3/dist-packages/jupyter_client/multikernelmanager.py", line 434,
in _async_restart_kernel
         await ensure_async(kernel.restart_kernel(now=now))
                            ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^
       File "/usr/lib/python3/dist-packages/jupyter_core/utils/__init__.py",
line 171, in wrapped
         return _runner_map[name].run(inner)
                ~~~~~~~~~~~~~~~~~~~~~^^^^^^^
       File "/usr/lib/python3/dist-packages/jupyter_core/utils/__init__.py",
line 128, in run
         return fut.result(None)
                ~~~~~~~~~~^^^^^^
       File "/usr/lib/python3.14/concurrent/futures/_base.py", line 454, in result
         return self.__get_result()
                ~~~~~~~~~~~~~~~~~^^
       File "/usr/lib/python3.14/concurrent/futures/_base.py", line 396, in
__get_result
         raise self._exception
       File "/usr/lib/python3.14/asyncio/tasks.py", line 289, in
__step_run_and_handle_result
         result = coro.send(None)
       File "/usr/lib/python3/dist-packages/jupyter_client/manager.py", line
595, in _async_restart_kernel
         await self._async_shutdown_kernel(now=now, restart=True)
       File "/usr/lib/python3/dist-packages/jupyter_client/manager.py", line 97,
in wrapper
         raise e
       File "/usr/lib/python3/dist-packages/jupyter_client/manager.py", line 88,
in wrapper
         out = await method(self, *args, **kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
       File "/usr/lib/python3/dist-packages/jupyter_client/manager.py", line
557, in _async_shutdown_kernel
         await self._async_finish_shutdown(restart=restart)
       File "/usr/lib/python3/dist-packages/jupyter_client/manager.py", line
480, in _async_finish_shutdown
         await asyncio.wait_for(
             self._async_wait(pollinterval=pollinterval), timeout=waittime / 2
         )
       File "/usr/lib/python3.14/asyncio/tasks.py", line 487, in wait_for
         async with timeouts.timeout(timeout):
                    ~~~~~~~~~~~~~~~~^^^^^^^^^
       File "/usr/lib/python3.14/asyncio/timeouts.py", line 89, in __aenter__
         raise RuntimeError("Timeout should be used inside a task")
     RuntimeError: Timeout should be used inside a task
[E 13:01:45.855 NotebookApp] {
       "Host": "localhost:8079",
       "Accept": "application/json, text/javascript, */*; q=0.01",
       "Referer": "http://localhost:8079/notebooks/discrete_laplacian.ipynb",
       "User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:152.0) Gecko/20100101
Firefox/152.0"
     }
[E 13:01:45.855 NotebookApp] 500 POST
/api/kernels/b875b6cf-ffab-4e7f-8f0f-70f7882f08ea/restart (127.0.0.1)
10.550000ms referer=http://localhost:8079/notebooks/discrete_laplacian.ipynb


Do you have any idea? Does it need some adaption in package
python3-jupyter-client (version 8.8.0-1) (file:
/usr/lib/python3/dist-packages/jupyter_client/manager.py) to work with python 3.14?

Regards,
Jörg.