Traitlets AttributeError: 'super' object has no attribute '_static_custom_path_default'

[gh-ahardin]

Hi! I just updated to Jupyter 5, jupyterhub 0.6.1 and it broke my setup with a two errors when logging in.
Spawning jupyterhub-singleuser --user=aaron --port=60827 --cookie-name=jupyter-hub-token-aaron --base-url=/user/aaron --hub-host= --hub-prefix=/hub/ --hub-api-url=http://127.0.0.1:8081/hub/api --ip=127.0.0.1

Traceback (most recent call last):
  File "/usr/local/lib/python3.5/dist-packages/traitlets/traitlets.py", line 528, in get
    value = obj._trait_values[self.name]
KeyError: 'static_custom_path'

During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/usr/local/bin/jupyterhub-singleuser", line 297, in <module>
    main()
  File "/usr/local/bin/jupyterhub-singleuser", line 293, in main
    return SingleUserNotebookApp.launch_instance()
  File "/usr/local/lib/python3.5/dist-packages/jupyter_core/application.py", line 267, in launch_instance
    return super(JupyterApp, cls).launch_instance(argv=argv, **kwargs)
  File "/usr/local/lib/python3.5/dist-packages/traitlets/config/application.py", line 657, in launch_instance
    app.initialize(argv)
  File "<decorator-gen-7>", line 2, in initialize
  File "/usr/local/lib/python3.5/dist-packages/traitlets/config/application.py", line 87, in catch_config_error
    return method(app, *args, **kwargs)
  File "/usr/local/lib/python3.5/dist-packages/notebook/notebookapp.py", line 1296, in initialize
    self.init_webapp()
  File "/usr/local/bin/jupyterhub-singleuser", line 268, in init_webapp
    super(SingleUserNotebookApp, self).init_webapp()
  File "/usr/local/lib/python3.5/dist-packages/notebook/notebookapp.py", line 1093, in init_webapp
    self.jinja_environment_options
  File "/usr/local/lib/python3.5/dist-packages/notebook/notebookapp.py", line 167, in __init__
    default_url, settings_overrides, jinja_env_options)
  File "/usr/local/lib/python3.5/dist-packages/notebook/notebookapp.py", line 220, in init_settings
    static_custom_path=jupyter_app.static_custom_path,
  File "/usr/local/lib/python3.5/dist-packages/traitlets/traitlets.py", line 556, in __get__
    return self.get(obj, cls)
  File "/usr/local/lib/python3.5/dist-packages/traitlets/traitlets.py", line 535, in get
    value = self._validate(obj, dynamic_default())
  File "/usr/local/bin/jupyterhub-singleuser", line 239, in _static_custom_path_default
    path = super(SingleUserNotebookApp, self)._static_custom_path_default()
AttributeError: 'super' object has no attribute '_static_custom_path_default'

[minrk]

To work with notebook 5.0, jupyterhub-singleuser must be upgraded to at least 0.7:

pip install --upgrade jupyterhub

[gh-ahardin]

That is how I upgraded jupyterhub initially. To fix my issue I had to run it again and then jupyterhub upgrade-db.

[ZelphirKaltstahl]

@minrk "at least" as in "0.7.x is guaranteed to work." or as in "It might work with 0.7.0, but if not, try an even newer version." ? I am working with a slightly modified version forked from 0.7.0, and I get that same error, when having notebook servers 5.0.0. Afaik I never modified anything with regard to notebook format or communication protocol in my modified JH.

[minrk]

@ZelphirKaltstahl The _static_custom_path_default code does not occur in jupyterhub-singleuser in 0.7.0. If you have the exact same traceback, then the fact that the error is in /usr/local/bin/jupyterhub-singleuser itself (as opposed to site-packages/jupyterhub/singleuser.py) suggests that you still have the jupyterhub-singleuser entrypoint from an earlier installation. You might try removing and reinstalling JupyterHub (and take care to note where it installs jupyterhub-singleuser).

[ZelphirKaltstahl]

@minrk Great help, thanks, will check that out.

[ZelphirKaltstahl]

@minrk I checked:

diff <0.7.0 file> <my current file>

shows 0 differences. Seems I already have the 0.7.0 version of the file in my JupyterHub. When I run my JupyterHub, I actually create a Docker container and run that, so all the files in the running JupyterHub come from when I built the Docker image. I built the image today and did not touch that singleuser.py file in months. It shows no differences to the file you linked with the GNU diff tool.

Is there something else, that could be the cause of this?

[minrk]

Is there something else, that could be the cause of this?

I don't believe so. If you have jupyterhub 0.7.0 or greater, the jupyterhub-singleuser script is only a few lines:

#!/prefix/bin/python

from jupyterhub.singleuser import main

if __name__ == '__main__':
    main()

So a traceback in that file means you have jupyterhub-singleuser from pre-0.7. It's possible that you have installed the current jupyterhub, but the old jupyterhub-singleuser script is still present and still being launched. You might try searching for it in your container:

find / -name jupyterhub-singleuser
# or
which -a jupyterhub-singleuser

[ZelphirKaltstahl]

@minrk I misread your previous comment, I'll have to check again, thanks.

[ZelphirKaltstahl]

My jupyterhub-singleuser file is under ./jupyterhub/scripts/jupyterhub-singleuser in the jupyterhub folder.
it has the following content:

#!/usr/bin/env python3

from jupyterhub.singleuser import main

if __name__ == '__main__':
    main()

My error is precisely the following:

Traceback (most recent call last):
  File "/opt/conda/lib/python3.6/site-packages/traitlets/traitlets.py", line 528, in get
    value = obj._trait_values[self.name]
KeyError: 'static_custom_path'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/bin/jupyterhub-singleuser", line 297, in <module>
    main()
  File "/usr/local/bin/jupyterhub-singleuser", line 293, in main
    return SingleUserNotebookApp.launch_instance()
  File "/opt/conda/lib/python3.6/site-packages/jupyter_core/application.py", line 267, in launch_instance
    return super(JupyterApp, cls).launch_instance(argv=argv, **kwargs)
  File "/opt/conda/lib/python3.6/site-packages/traitlets/config/application.py", line 657, in launch_instance
    app.initialize(argv)
  File "<decorator-gen-7>", line 2, in initialize
  File "/opt/conda/lib/python3.6/site-packages/traitlets/config/application.py", line 87, in catch_config_error
    return method(app, *args, **kwargs)
  File "/opt/conda/lib/python3.6/site-packages/notebook/notebookapp.py", line 1296, in initialize
    self.init_webapp()
  File "/usr/local/bin/jupyterhub-singleuser", line 268, in init_webapp
    super(SingleUserNotebookApp, self).init_webapp()
  File "/opt/conda/lib/python3.6/site-packages/notebook/notebookapp.py", line 1093, in init_webapp
    self.jinja_environment_options
  File "/opt/conda/lib/python3.6/site-packages/notebook/notebookapp.py", line 167, in __init__
    default_url, settings_overrides, jinja_env_options)
  File "/opt/conda/lib/python3.6/site-packages/notebook/notebookapp.py", line 220, in init_settings
    static_custom_path=jupyter_app.static_custom_path,
  File "/opt/conda/lib/python3.6/site-packages/traitlets/traitlets.py", line 556, in __get__
    return self.get(obj, cls)
  File "/opt/conda/lib/python3.6/site-packages/traitlets/traitlets.py", line 535, in get
    value = self._validate(obj, dynamic_default())
  File "/usr/local/bin/jupyterhub-singleuser", line 239, in _static_custom_path_default
    path = super(SingleUserNotebookApp, self)._static_custom_path_default()
AttributeError: 'super' object has no attribute '_static_custom_path_default'

So somehow another jupyterhub-singleuser script is created inside the docker container at /usr/local/bin/jupyterhub-singleuser. Is this part of the installation with pip install -e . inside the JupyterHub directory?

In my Dockerfile I am doing:

WORKDIR /srv/
COPY jupyterhub /srv/jupyterhub
WORKDIR /srv/jupyterhub/
RUN python setup.py js \
 && pip install -e .

Which copies the JupyterHub from the Docker context into the Docker image and then installs JupyterHub in it. Inside that copied JupyterHub is where I checked for the content of jupyterhub-singleuser, which I described above.

However, I am clueless at this moment, where the /usr/local/bin/jupyterhub-singleuser comes from.

[minrk]

Can you share the rest of your Dockerfile? What's your base image (FROM ...)? If you are installing jupyterhub from 0.7, then the file with these contents won't be created, so it is presumably leftover from a previous installation. Since I see from your traceback that you are using conda in /opt/conda and single-user is installed at /usr/local/bin/, installing jupyterhub won't go in /usr/local, it will go somewhere like /opt/conda/bin/jupyterhub-singleuser. The commands I pasted above:

find / -name jupyterhub-singleuser
# or
which -a jupyterhub-singleuser

should point to the possibility of more than one install. You can also try removing /usr/local/bin/jupyterhub-singleuser prior to installing JupyterHub, to make sure this file isn't present.

[ZelphirKaltstahl]

@minrk I'll see what I can do. I might also try to get the newest stable running in my setup. It is difficult to know if the changes I have in the 0.7.0 affect this or not. In theory they should not, since I never touched anything related to notebook format though. When I have more information, I'll post.

[ZelphirKaltstahl]

@minrk I figured out where the old file came from. I was downloading the script of 0.6.1 in my Dockerfile with wget. That download was copied from the JupyterHub Docker image Dockerfile from DockerHub months ago and since I did not have such file in my Docker context (what I mean by that is "files next to the Dockerfile, which are copied into the Docker image") when building the Notebook Docker images, I never saw that file … Now updated that download and will see how it goes.

[ZelphirKaltstahl]

@minrk The problem is gone with the newer file, just like you said it should.