TeX macros don't transfer to Latex

[stoffprof]

It appears that TeX macros defined following the example are not included in the latex created by

jb build mybookname/ --builder latex

as described here.

Specifically, I have a line in _config.yml that says

    macros:
      "R": "\\mathbb{R}"

This works fine in generating HTML. But the generated latex file gets hung up on \R. Manually adding

\newcommand\R{\mathbb{R}}

to the .tex file fixes the problem.