ERROR:tornado.general:Uncaught exception in ZMQStream callback

Description

What steps will reproduce the problem?

1. Open spyder.
2. Tries to connect to the kernel.
3. Shows the error.

What is the expected output? What do you see instead?

An error ocurred while starting the kernel ERROR:tornado.general:Uncaught exception in ZMQStream callback Traceback (most recent call last): File “/usr/local/lib/python3.5/dist‑packages/zmq/eventloop/zmqstream.py”, line 432, in _run_callback callback(*args, **kwargs) File “/usr/local/lib/python3.5/dist‑packages/tornado/stack_context.py”, line 276, in null_wrapper return fn(*args, **kwargs) File “/home/adityamagarde/.local/lib/python3.5/site‑packages/ipykernel/kernelbase.py”, line 283, in dispatcher return self.dispatch_shell(stream, msg) File “/home/adityamagarde/.local/lib/python3.5/site‑packages/ipykernel/kernelbase.py”, line 233, in dispatch_shell self.pre_handler_hook() File “/home/adityamagarde/.local/lib/python3.5/site‑packages/ipykernel/kernelbase.py”, line 248, in pre_handler_hook self.saved_sigint_handler = signal(SIGINT, default_int_handler) File “/usr/lib/python3.5/signal.py”, line 47, in signal handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler)) ValueError: signal only works in main thread ERROR:tornado.general:Uncaught exception in zmqstream callback Traceback (most recent call last): File “/usr/local/lib/python3.5/dist‑packages/zmq/eventloop/zmqstream.py”, line 450, in _handle_events self._handle_recv() File “/usr/local/lib/python3.5/dist‑packages/zmq/eventloop/zmqstream.py”, line 480, in _handle_recv self._run_callback(callback, msg) File “/usr/local/lib/python3.5/dist‑packages/zmq/eventloop/zmqstream.py”, line 432, in _run_callback callback(*args, **kwargs) File “/usr/local/lib/python3.5/dist‑packages/tornado/stack_context.py”, line 276, in null_wrapper return fn(*args, **kwargs) File “/home/adityamagarde/.local/lib/python3.5/site‑packages/ipykernel/kernelbase.py”, line 283, in dispatcher return self.dispatch_shell(stream, msg) File “/home/adityamagarde/.local/lib/python3.5/site‑packages/ipykernel/kernelbase.py”, line 233, in dispatch_shell self.pre_handler_hook() File “/home/adityamagarde/.local/lib/python3.5/site‑packages/ipykernel/kernelbase.py”, line 248, in pre_handler_hook self.saved_sigint_handler = signal(SIGINT, default_int_handler) File “/usr/lib/python3.5/signal.py”, line 47, in signal handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler)) ValueError: signal only works in main thread ERROR:tornado.application:Exception in callback functools.partial(.null_wrapper at 0x7f95db138f28>) Traceback (most recent call last): File “/usr/local/lib/python3.5/dist‑packages/tornado/ioloop.py”, line 760, in _run_callback ret = callback() File “/usr/local/lib/python3.5/dist‑packages/tornado/stack_context.py”, line 276, in null_wrapper return fn(*args, **kwargs) File “/usr/local/lib/python3.5/dist‑packages/zmq/eventloop/zmqstream.py”, line 536, in self.io_loop.add_callback(lambda : self._handle_events(self.socket, 0)) File “/usr/local/lib/python3.5/dist‑packages/zmq/eventloop/zmqstream.py”, line 450, in _handle_events self._handle_recv() File “/usr/local/lib/python3.5/dist‑packages/zmq/eventloop/zmqstream.py”, line 480, in _handle_recv self._run_callback(callback, msg) File “/usr/local/lib/python3.5/dist‑packages/zmq/eventloop/zmqstream.py”, line 432, in _run_callback callback(*args, **kwargs) File “/usr/local/lib/python3.5/dist‑packages/tornado/stack_context.py”, line 276, in null_wrapper return fn(*args, **kwargs) File “/home/adityamagarde/.local/lib/python3.5/site‑packages/ipykernel/kernelbase.py”, line 283, in dispatcher return self.dispatch_shell(stream, msg) File “/home/adityamagarde/.local/lib/python3.5/site‑packages/ipykernel/kernelbase.py”, line 233, in dispatch_shell self.pre_handler_hook() File “/home/adityamagarde/.local/lib/python3.5/site‑packages/ipykernel/kernelbase.py”, line 248, in pre_handler_hook self.saved_sigint_handler = signal(SIGINT, default_int_handler) File “/usr/lib/python3.5/signal.py”, line 47, in signal handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler)) ValueError: signal only works in main thread Traceback (most recent call last): File “/home/adityamagarde/.local/lib/python3.5/site‑packages/spyder/utils/ipython/start_kernel.py”, line 241, in main() File “/home/adityamagarde/.local/lib/python3.5/site‑packages/spyder/utils/ipython/start_kernel.py”, line 237, in main kernel.start() File “/home/adityamagarde/.local/lib/python3.5/site‑packages/ipykernel/kernelapp.py”, line 477, in start ioloop.IOLoop.instance().start() File “/usr/local/lib/python3.5/dist‑packages/tornado/platform/asyncio.py”, line 112, in start self.asyncio_loop.run_forever() File “/usr/lib/python3.5/asyncio/base_events.py”, line 340, in run_forever raise RuntimeError(‘Event loop is running.’) RuntimeError: Event loop is running. Traceback (most recent call last): File “/home/adityamagarde/.local/lib/python3.5/site‑packages/spyder/utils/ipython/start_kernel.py”, line 241, in main() File “/home/adityamagarde/.local/lib/python3.5/site‑packages/spyder/utils/ipython/start_kernel.py”, line 237, in main kernel.start() File “/home/adityamagarde/.local/lib/python3.5/site‑packages/ipykernel/kernelapp.py”, line 477, in start ioloop.IOLoop.instance().start() File “/usr/local/lib/python3.5/dist‑packages/tornado/platform/asyncio.py”, line 112, in start self.asyncio_loop.run_forever() File “/usr/lib/python3.5/asyncio/base_events.py”, line 340, in run_forever raise RuntimeError(‘Event loop is running.’) RuntimeError: Event loop is running.

Please provide any additional information below I recently installed jupyter. Even that isn’t working I guess.

Version and main components

• Spyder Version: 3.2.3
• Python Version: 3.5.2
• Qt Versions: 4.8.7, PyQt4 (API v2) 4.11.4 on Linux

Dependencies

pyflakes >=0.6.0 :  1.6.0 (OK)
pycodestyle >=2.3:  2.3.1 (OK)
pygments >=2.0   :  2.2.0 (OK)
pandas >=0.13.1  :  0.17.1 (OK)
numpy >=1.7      :  1.13.3 (OK)
sphinx >=0.6.6   :  1.6.4 (OK)
rope >=0.9.4     :  0.10.7 (OK)
jedi >=0.9.0     :  0.11.0 (OK)
psutil >=0.3     :  5.3.1 (OK)
nbconvert >=4.0  :  5.3.1 (OK)
sympy >=0.7.3    :  None (NOK)
cython >=0.21    :  None (NOK)
qtconsole >=4.2.0:  4.3.1 (OK)
IPython >=4.0    :  6.2.1 (OK)
pylint >=0.25    :  1.7.4 (OK)

[xiaokunx]

downgrading tornado to 4.5.3 does not solve the problem, upgrading ipykernel from 4.6.1 to 4.8.2 solve the problem for me.

[Qberto]

Like @xiaokunx, downgrading tornado to 4.5.3 did not resolve the issue for me, while upgrading ipykernel solved the problem. conda upgrade ipykernel should do the trick.