Ipython: IPython 5.0.0b2 AssertionError desde prompt_toolkit.buffer

Parece que IPython se bloqueará si ha escrito completamente la palabra que desea, pero intente completar con tabulación de todos modos y luego presionenuevamente para anular la selección del cuadro de diálogo de finalización de tabulación.

Ejemplo:

1. escriba "Importar IPython" en IPython
2. prensapara habilitar la finalización de tabulación
3. prensade nuevo para anular la selección de la pestaña de finalización
4. prensa

Aquí hay un screencast de la consola que muestra los pasos de replicación para este error: https://asciinema.org/a/7890yzftp8lzdjzxasrpvdnil

Y el stacktrace:

Traceback (most recent call last):
  File "/tmp/foo/bin/ipython", line 11, in <module>
    sys.exit(start_ipython())
  File "/tmp/foo/lib/python3.5/site-packages/IPython/__init__.py", line 119, in start_ipython
    return launch_new_instance(argv=argv, **kwargs)
  File "/tmp/foo/lib/python3.5/site-packages/traitlets/config/application.py", line 596, in launch_instance
    app.start()
  File "/tmp/foo/lib/python3.5/site-packages/IPython/terminal/ipapp.py", line 348, in start
    self.shell.mainloop()
  File "/tmp/foo/lib/python3.5/site-packages/IPython/terminal/ptshell.py", line 398, in mainloop
    self.interact()
  File "/tmp/foo/lib/python3.5/site-packages/IPython/terminal/ptshell.py", line 381, in interact
    code = self.prompt_for_code()
  File "/tmp/foo/lib/python3.5/site-packages/IPython/terminal/ptshell.py", line 324, in prompt_for_code
    pre_run=self.pre_prompt, reset_current_buffer=True)
  File "/tmp/foo/lib/python3.5/site-packages/prompt_toolkit/interface.py", line 387, in run
    self.eventloop.run(self.input, self.create_eventloop_callbacks())
  File "/tmp/foo/lib/python3.5/site-packages/prompt_toolkit/eventloop/posix.py", line 154, in run
    t()
  File "/tmp/foo/lib/python3.5/site-packages/prompt_toolkit/eventloop/posix.py", line 82, in read_from_stdin
    inputstream.feed(data)
  File "/tmp/foo/lib/python3.5/site-packages/prompt_toolkit/terminal/vt100_input.py", line 376, in feed
    self._input_parser.send(c)
  File "/tmp/foo/lib/python3.5/site-packages/prompt_toolkit/terminal/vt100_input.py", line 295, in _input_parser_generator
    self._call_handler(match, prefix)
  File "/tmp/foo/lib/python3.5/site-packages/prompt_toolkit/terminal/vt100_input.py", line 328, in _call_handler
    self.feed_key_callback(KeyPress(key, insert_text))
  File "/tmp/foo/lib/python3.5/site-packages/prompt_toolkit/interface.py", line 916, in feed_key
    self._active_cli.input_processor.feed_key(key_press)
  File "/tmp/foo/lib/python3.5/site-packages/prompt_toolkit/key_binding/input_processor.py", line 174, in feed_key
    self._process_coroutine.send(key_press)
  File "/tmp/foo/lib/python3.5/site-packages/prompt_toolkit/key_binding/input_processor.py", line 146, in _process
    self._call_handler(matches[-1], key_sequence=buffer)
  File "/tmp/foo/lib/python3.5/site-packages/prompt_toolkit/key_binding/input_processor.py", line 190, in _call_handler
    handler.call(event)
  File "/tmp/foo/lib/python3.5/site-packages/prompt_toolkit/key_binding/registry.py", line 32, in call
    return self.handler(event)
  File "/tmp/foo/lib/python3.5/site-packages/IPython/terminal/ptshell.py", line 187, in _
    b.apply_completion(cs.current_completion)
  File "/tmp/foo/lib/python3.5/site-packages/prompt_toolkit/buffer.py", line 762, in apply_completion
    assert isinstance(completion, Completion)
AssertionError

If you suspect this is an IPython bug, please report it at:
    https://github.com/ipython/ipython/issues
or send an email to the mailing list at [email protected]

You can print a more detailed traceback right now with "%tb", or use "%debug"
to interactively debug it.

Extra-detailed tracebacks for bug-reporting purposes can be enabled via:
    %config Application.verbose_crash=True