Binder badge links give 404 errors from survey result notebooks

[GenevieveBuckley]

What happened:

When I click the binder badge included in the first few cells of the survey notebooks

• Survey notebooks: https://github.com/dask/dask-examples/tree/main/surveys
• Example binder link: https://mybinder.org/v2/gh/dask/dask-examples/main?filepath=surveys/2020.ipynb

What you expected to happen:

I expected the survey notebook to open in binder.

Anything else we need to know?:

When I go to https://mybinder.org/ and input just the repository link: https://github.com/dask/dask-examples then the binder hub for the whole repository does start.

But when I go to https://mybinder.org/ and input the repository link: https://github.com/dask/dask-examples AND the branch "main" AND the filepath "surveys/2020.ipynb" then I get a 404 error page instead of binder launching.

What am I doing wrong? I thought that was the way to get a direct binder link for a specific notebook.

[GenevieveBuckley]

I found these relevant issues:

• Preview from nbviewer while loading Binder shows 404 when giving a notebook-file path jupyterhub/binderhub#616
• 404 nbviewer before binder starts jupyterhub/mybinder.org-user-guide#167
• Getting filepath right for notebook preview jupyterhub/binderhub#622

They suggest:

• making sure there is no leading / in the notebook filepath
• waiting longer to see if the 404 error turns into a notebook at some point (I waited >5 minutes, also refreshed the page after that interval)

Neither of these suggestions helped in our case.

[GenevieveBuckley]

Unsure if the change where mybinder now uses JupyterLab by default is relevant or not: https://discourse.jupyter.org/t/mybinder-org-using-jupyterlab-by-default/10715

EDIT: Nope, using the tricks to get the old interface doesn't help, we still get a 404 error.

[GenevieveBuckley]

This might be the answer: https://discourse.jupyter.org/t/bug-path-to-a-notebook-file-functionality-unexepectedly-changed-not-working-for-notebooks-in-subfolders/10811

EDIT: Yes, it works!

https://mybinder.org/v2/gh/dask/dask-examples/main?urlpath=%2Ftree%2Fsurveys%2F2020.ipynb

[GenevieveBuckley]

Copying the relevant portion of my comment from the linked PR:

[The binder links] broke for two reasons:

1. The dask-examples "main" branch was recently renamed (previously named "master"), and
2. A backwards incompatible change happened in the way binder generates/parses links (see here for more details)

Neither of these should be a problem going forward. However, we will need to be careful with the way people generate binder badges for dask-examples - if you use https://mybinder.org/ it will give you a link that only works for newer versions.
We can either:

• Use the link formatting with urlpath like in this PR, or
• Update the pinned dependencies over at dask-examples to be more modern