At this point I'd be tempted to harbor a guess that it's a client side dependency, or something further upstream (eg one of the JS libraries) but I can't be certain. Opening an issue to keep track of it and see if there are any guesses on the root cause?
In some parts of the book, such as 3.2 Nonlinear axes what used to be rendered LaTeX are now
Math Processing Error
.Tracing it to the Rmd file, it would appear that these are valid notations:
At this point I'd be tempted to harbor a guess that it's a client side dependency, or something further upstream (eg one of the JS libraries) but I can't be certain. Opening an issue to keep track of it and see if there are any guesses on the root cause?