"manual grading" screen unable to format any math containing a prime symbol `'`

Operating system

MacOS 10.14.4 (18E226)

nbgrader --version

0.6.1

jupyter notebook --version

6.0.3

Expected behavior

In one of the courses I am teaching, we wanted to use nbgrader to automate some of the grading. Until now it’s working beautifully – thanks for this. For this week, we have a notebook containing function derivatives, like so: $$ y’(x) = f(x, y(x)) $$ which sets correctly in my source and release versions, looking a little like this:

Actual behaviour

If I then open a student submission, at first I am able to see the math, like so,

but when it is about to replace the text with a MathJax formula, it looks like so:

When this happens, I get these errors in my terminal:

[W 17:49:18.142 NotebookApp] 404 GET /static/components/MathJax/jax/output/HTML-CSS/fonts/STIX/fontdata.js?V=2.7.7 (::1) 2.53ms referer=http://localhost:8889/formgrader/submissions/ccc77ef030ea4ae5bda1d7d0e787089c/?index=0
[W 17:49:20.909 NotebookApp] 404 GET /static/components/MathJax/fonts/HTML-CSS/TeX/otf/MathJax_Script-Regular.otf (::1) 1.49ms referer=http://localhost:8889/formgrader/submissions/ccc77ef030ea4ae5bda1d7d0e787089c/?index=0

This only happens in the formulas containing a prime/derivative sign, weirdly enough.

Steps to reproduce the behavior

I get the same results using a different browser and also using a different machine (MacOS 10.14.6, jupyter 6.0.2, nbgrader 0.6.1)

I am not sure how I can add a MWE but if it seems useful later I can try making a test assignment and a submission, or I could share an anonymized submission from the real assignment. Please let me know which one is preferable.

[Jannertje]

OK pardon me, this is a duplicate of #426 – I am willing to help search for the root cause instead of (stupidly) reinstalling MathJax?

[brichet]

Thanks for reporting this. It may also be related to https://github.com/jupyter/nbgrader/issues/1622.

Can you try replacing the mathjax import in your local installation to see if that solves the problem ?

The line is : https://github.com/jupyter/nbgrader/blob/90f749b8ea0514700dfa28fe560bbb489746e26f/nbgrader/server_extensions/formgrader/templates/formgrade/index.html.j2#L18

to replace by

{{ mathjax() }} 

This will use the default mathjax from nbconvert. On my side the 404 error disappear and mathjax seems to work correctly.