[Python-modules-team] Bug#894033: jupyter-notebook: jupyter notebook: IOLoop has no attribute initialized

[r.ductor]

Package: jupyter-notebook
Version: 5.4.0-1
Severity: grave
Justification: renders package unusable

Dear Maintainer,

jupyter notebook crashes on start:

$ jupyter notebook
Traceback (most recent call last):
  File "/usr/bin/jupyter-notebook", line 11, in <module>
    load_entry_point('notebook==5.4.0', 'console_scripts', 'jupyter-notebook')()
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 587, in load_entry_point
    return get_distribution(dist).load_entry_point(group, name)
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2800, in load_entry_point
    return ep.load()
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2431, in load
    return self.resolve()                                                                                      
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2437, in resolve                       
    module = __import__(self.module_name, fromlist=['__name__'], level=0)                                      
  File "/usr/lib/python3/dist-packages/notebook/notebookapp.py", line 45, in <module>                          
    ioloop.install()                                                                                           
  File "/usr/lib/python3/dist-packages/zmq/eventloop/ioloop.py", line 210, in install                          
    assert (not ioloop.IOLoop.initialized()) or \                                                              
AttributeError: type object 'IOLoop' has no attribute 'initialized'


-- System Information:
Debian Release: buster/sid
  APT prefers testing
  APT policy: (900, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 4.14.0-3-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages jupyter-notebook depends on:
ii  jupyter-core      4.4.0-2
ii  python3           3.6.4-1
ii  python3-notebook  5.4.0-1

jupyter-notebook recommends no packages.

jupyter-notebook suggests no packages.

-- no debconf information