No latex display in the notebook when offline

[egourgoulhon]

Steps To Reproduce

With Sage 10.3.beta2 running on a computer that is offline (not connected to internet), open a new Jupyter notebook with sage -n and type the following code:

%display latex
sin(x^2)

Expected Behavior

The output should be a typeset formula.

Actual Behavior

The output is raw latex:

\(\displaystyle \sin\left(x^{2}\right)\)

Additional Information

There is no such issue with Sage 10.2. It is most likely due to the Notebook upgrade performed in #36129

Environment

- **OS**: Ubuntu 22.04
- **Sage Version**: 10.3.beta2

Checklist

• I have searched the existing issues for a bug report that matches the one I want to file, without success.
• I have read the documentation and troubleshoot guide

[egourgoulhon]

A data point: with Sage 10.2, the offline latex display works with jupyterlab (sage -n jupyterlab) as well, while with Sage 10.3.beta6, it works neither with jupyter (now emulated by jupyterlab) nor jupyterlab.

@mkoeppe, @kwankyu do you have any idea or suggestion?

[kwankyu]

I cannot reproduce this with 10.3.beta6 on mac. Is it only on Ubuntu?

[egourgoulhon]

I cannot reproduce this with 10.3.beta6 on mac.

Thanks for the feedback.

Is it only on Ubuntu?

I cannot say. I've tested it on 2 computers both running Ubuntu 22.04. I'll send a query for further tests on sage-devel.

[egourgoulhon]

I'll send a query for further tests on sage-devel.

Here is the post:
https://groups.google.com/g/sage-devel/c/sSBryLVqQk4

[egourgoulhon]

Another data point: there is no error message in the console from which sage -n was run when the computer is offline. Simply the MathJax display fails silently.

[egourgoulhon]

For reference, I copy here an extract of https://groups.google.com/g/sage-devel/c/sSBryLVqQk4/m/xepfECrvAQAJ

• Sage 10.2 uses Ubuntu 22.04's MathJax (v2.7.9), so there is no issue when the computer is offline.
• Sage 10.3.beta* refuses to use Ubuntu 22.04's MathJax and the MathJax 3.2.0 shipped with Sage is not used either

[egourgoulhon]

For reference, the post on Jupyter forum:
https://discourse.jupyter.org/t/notebook-with-mathjax-without-internet-connection/23958

[kwankyu]

"blocker" label is getting overloaded too much.

Let's use "blocker" only for PRs and use "critical" for issues.

[dimpase]

I think this is due to sticking with MathJax-2 rather than moving to MathJax-3 (well, in the latter case you have non-wrapped, although scroll-able, long formlae).

Jupyterlab ships with a copy of MathJax-3, so installing mathjax2 overrides it (but breaks off-line working).

[mkoeppe]

I've added this to https://github.com/sagemath/sage/wiki/Sage-10.3-Release-Tour#known-problems-and-workarounds

[mkoeppe]

Some relevant places in the code

• https://github.com/jupyter/notebook/blame/main/notebook/app.py#L89C9-L89C20 -- this indicates there is a configuration value mathjax_url that we should be able to set somehow; the default points to the CDN.
• the actual renderer https://github.com/jupyterlab/jupyter-renderers/tree/main/packages/mathjax2-extension has no CDN URL but only refers to the page config variable fullMathjaxUrl https://github.com/jupyterlab/jupyter-renderers/blob/main/packages/mathjax2-extension/src/index.ts#L34