ipython help notebook -> KeyError: 'KernelManager'

[twmr]

On master ipython help notebook outputs the following traceback (python 2.7.3)

....
....
--no-stderr
    redirect stderr to the null device
Traceback (most recent call last):
  File "/bin/ipython", line 7, in <module>
    launch_new_instance()
  File "/home/thomas/gitrepos/ipython/IPython/frontend/terminal/ipapp.py", line 388, in launch_new_instance
    app.initialize()
  File "<string>", line 2, in initialize
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 84, in catch_config_error
    return method(app, *args, **kwargs)
  File "/home/thomas/gitrepos/ipython/IPython/frontend/terminal/ipapp.py", line 313, in initialize
    super(TerminalIPythonApp, self).initialize(argv)
  File "<string>", line 2, in initialize
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 84, in catch_config_error
    return method(app, *args, **kwargs)
  File "/home/thomas/gitrepos/ipython/IPython/core/application.py", line 323, in initialize
    self.parse_command_line(argv)
  File "/home/thomas/gitrepos/ipython/IPython/frontend/terminal/ipapp.py", line 308, in parse_command_line
    return super(TerminalIPythonApp, self).parse_command_line(argv)
  File "<string>", line 2, in parse_command_line
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 84, in catch_config_error
    return method(app, *args, **kwargs)
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 420, in parse_command_line
    return self.initialize_subcommand(subc, subargv)
  File "<string>", line 2, in initialize_subcommand
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 84, in catch_config_error
    return method(app, *args, **kwargs)
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 359, in initialize_subcommand
    self.subapp.initialize(argv)
  File "<string>", line 2, in initialize
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 84, in catch_config_error
    return method(app, *args, **kwargs)
  File "/home/thomas/gitrepos/ipython/IPython/frontend/html/notebook/notebookapp.py", line 590, in initialize
    super(NotebookApp, self).initialize(argv)
  File "<string>", line 2, in initialize
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 84, in catch_config_error
    return method(app, *args, **kwargs)
  File "/home/thomas/gitrepos/ipython/IPython/core/application.py", line 323, in initialize
    self.parse_command_line(argv)
  File "/home/thomas/gitrepos/ipython/IPython/frontend/html/notebook/notebookapp.py", line 446, in parse_command_line
    super(NotebookApp, self).parse_command_line(argv)
  File "<string>", line 2, in parse_command_line
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 84, in catch_config_error
    return method(app, *args, **kwargs)
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 433, in parse_command_line
    self.print_help('--help-all' in interpreted_argv)
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 295, in print_help
    self.print_options()
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 268, in print_options
    self.print_alias_help()
  File "/home/thomas/gitrepos/ipython/IPython/config/application.py", line 232, in print_alias_help
    cls = classdict[classname]
KeyError: 'KernelManager'

[minrk]

fixed by #2861