When running "jupyter notebook", no functional kernel can be provided to start hacking on a notebook. The output keeps reading: [I 22:53:23.549 NotebookApp] KernelRestarter: restarting kernel (4/5), new random ports Traceback (most recent call last): File "/usr/lib64/python2.7/runpy.py", line 174, in _run_module_as_main "__main__", fname, loader, pkg_name) File "/usr/lib64/python2.7/runpy.py", line 72, in _run_code exec code in run_globals File "/usr/lib64/python2.7/site-packages/ipykernel_launcher.py", line 16, in <module> app.launch_new_instance() File "/usr/lib64/python2.7/site-packages/traitlets/config/application.py", line 658, in launch_instance app.start() File "/usr/lib64/python2.7/site-packages/ipykernel/kernelapp.py", line 477, in start ioloop.IOLoop.instance().start() File "/usr/lib64/python2.7/site-packages/tornado/ioloop.py", line 937, in start raise RuntimeError("IOLoop is already running") RuntimeError: IOLoop is already running This upstream bug issue might be related — https://github.com/jupyter/notebook/issues/3397 — however, portage does not me downgrade tornado to 4.5.3 as that ticket might suggest and in a fresh virtualenv, "jupyter notebook" works fin with either Tornado 5.1 and 6.0.2.
While downgrading tornado to 4.5.3 fixed the IOLoop error for me, I was also getting the following error: ERROR:tornado.general:Uncaught exception in ZMQStream callback Traceback (most recent call last): File "/usr/lib64/python3.6/site-packages/zmq/eventloop/zmqstream.py", line 432, in _run_callback callback(*args, **kwargs) File "/usr/lib64/python3.6/site-packages/tornado/stack_context.py", line 277, in null_wrapper return fn(*args, **kwargs) File "/usr/lib64/python3.6/site-packages/ipykernel/kernelbase.py", line 283, in dispatcher return self.dispatch_shell(stream, msg) File "/usr/lib64/python3.6/site-packages/ipykernel/kernelbase.py", line 233, in dispatch_shell self.pre_handler_hook() File "/usr/lib64/python3.6/site-packages/ipykernel/kernelbase.py", line 248, in pre_handler_hook self.saved_sigint_handler = signal(SIGINT, default_int_handler) File "/usr/lib64/python3.6/signal.py", line 47, in signal handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler)) ValueError: signal only works in main thread which according to upstream https://github.com/ipython/ipykernel/issues/335 I fixed by upgrading ipykernel to 4.8.2. When I subsequently upgraded tornado back to 5.1 everything worked fine. Maybe ipykernel 4.8.2 should be stabilised?
Closing bugs reported for old versions, no longer in ::gentoo. Please reopen if you can still reproduce.
