Trying to use latest JupyterLab in TLJH gets me a blank page

JupyterHub The Littlest JupyterHub
1

Hi! I tried using @yuvipanda WIP pull request Upgrade to JupyterLab 3.0 by yuvipanda · Pull Request #647 · jupyterhub/the-littlest-jupyterhub · GitHub to use the latest JupyterLab in TLJH. However, when I run it and I try to enter the lab interface, I get a blank webpage.

The Firefox developer tools show an error: Uncaught (in promise) TypeError: t.map is not a function

Screenshot from 2021-02-02 10-38-09
Screenshot from 2021-02-02 10-38-09704×104 9.25 KB

And the source is the minified main.722fcaa2f23743df70b8.js, whose first characters are these:

(()=>{var e={37559:(e,t,r)=>{let a=null;function n(e){if(a===null){let e={};if(typeof document!=="undefined"&&document){const t=document.getElementById("jupyter-config-data")

Downgrading to jupyterlab<3 did the trick.

2

Does this error shoes up on JupyterLab startup?

Have you been able to try with the suggestions listed in the PR?

3

Hi @jtp , thanks! Yes, I saw your comments and tried those too, except the tornado part that you wrote a few minutes ago. However I’m not in a rush, I can try again when the final list of dependencies is agreed.

4

Right, but it’s great that you already started testing this PR.

Maybe some troubleshooting commands like pip list, jupyter labextension list or even jupyter troubleshoot can give more info?

5

Another one worth trying, still in the user environment where JupyterLab is installed, would be:

jupyter lab build --minimize=False

This should normally rebuild JupyterLab without minimizing the source, so hopefully the error message will be clearer.

6

I tried reproducing the problem on another machine but couldn’t do it. It looks like applying the PR as it stands now, upgrading tornado, and then doing a jupyter lab build --minimize=False as you advised, left the hub in a working state. All good, I guess! :slight_smile: Thanks for the help!

7

Nice!

This part is mostly for debugging normally.