Update jupyter-offlinenotebook to 0.2.1

[manics]

This includes the JupyterLab 3 extension that does not require a build step. It remains compatible with JupyterLab 2 (but the extension must be installed separately).

As far as JupyterLab 2 is concerned there is no change. For JupyterLab3 the extension is effectively pre-installed since it's part of the PyPI package, so it should "just work" if someone choose to install JupyterLab 3.

See also:

• Update to JupyterLab 3.0 jupyterlab/jupyterlab-demo#102 (comment)
• Update to JupyterLab 3.0 #996

[jtpio]

Thanks!

Will the jupyter lab build --minimize=False command below still trigger a new build? Maybe it's possible to not run it if the JupyterLab version is >= 3.0?

[manics]

I think that repo2docker:

1. Installs miniforge
2. Installs a default set of packages defined from the environment*.yml in https://github.com/jupyterhub/repo2docker/tree/d8a3d7fa0ac8b1ec151d473a86ca813535369a54/repo2docker/buildpacks/conda (which includes JupyterLab 2)
3. Installs the user environment, which is where JupyterLab would be upgraded

Hopefully someone will correct me if I'm wrong!

[manics]

The conda-forge package has also been updated to 0.2.0: https://anaconda.org/conda-forge/jupyter-offlinenotebook/files

So if we want we could switch to that as suggested in #846 #996
I'm happy to make that change in this PR if that's the preferred option.

[tomyun]

IIUC, switching to use conda-forge package in environment.yml may help solving #961.

[betatim]

I think that repo2docker:

1. Installs miniforge

2. Installs a default set of packages defined from the `environment*.yml` in [`d8a3d7f`/repo2docker/buildpacks/conda](https://github.com/jupyterhub/repo2docker/tree/d8a3d7fa0ac8b1ec151d473a86ca813535369a54/repo2docker/buildpacks/conda) (which includes JupyterLab 2)

3. Installs the user environment, which is where JupyterLab would be upgraded

I also think this is what happens.

That means that by default repo2docker runs with jupyterlab 2 and in order to install offline-notebook we have to run the build step. At a later point in the build process the user might install lab 3. The new thing here is that the user won't have to run the build step again. Right now lots of repos use a postBuild to re-run the build. This is what can be removed after we merge this PR.

[betatim]

Any idea why the (3.8, conda) tests fail with No matching distribution found for jupyter-offlinenotebook==0.2.0?

[manics]

My first guess was a stale PyPI cache, but I've re-run the tests and they're still failing so I'll need to investigate further.

[manics]

The failing test uses a Python 3.5 environment, but I set the minimum Python version to 3.6
https://github.com/manics/jupyter-offlinenotebook/blob/24c3429d06660a21f05c912a041479a33db66a77/setup.py#L96
I forgot that repo2docker mixes the Jupyter front end and the execution environment for Python 3.*.

I can think of a few options:

1. Use same strategy as installing the JupyterLab extension and allow it to fail: pip install jupyter-offlinenotebook==0.2.0 || true.
2. Change https://github.com/manics/jupyter-offlinenotebook/blob/24c3429d06660a21f05c912a041479a33db66a77/setup.py#L96 to python_requires>=3.5 and release 0.2.1. The previous release was missing a python_requires statement which is why it previously worked.
3. Switch to the conda package, which means different versions of jupyter-offlinenotebook could be used. The 3.5 environment could either use version 0.1.0, or we could just omit the extension since any Python 3.5 repositories will be quite old, and users probably won't miss this extension. The other 3.* environments would use 0.2.0.

1 is the least work. 3 is the most work, but I think it's worth doing if everyone's agreed. What do you think?

[manics]

Does anyone have a preference for any of the three options in #997 (comment) ? Otherwise I'll go with (3), switching to conda

[betatim]

I think using a conda package is good and the only downside is that it is more work to setup now. I think providing an older version is fine for Python 3.5.

[manics]

I'm closing this as it looks like #996 will be merged soon