Can I use revtex, babel + BibTex, and cleveref together?

Question

I am trying to write a paper with

• revtex4-2 document class (revtex4-2 2020/10/03 4.2e);
• .bib file specifying language field for some entries;
• cleveref package;
• custom theorem (using \newtheorem command and \Crefname for references in cleveref to work correctly).

This, however, results in a compilation failure. Here is a minimal example:

min.tex:

\documentclass{revtex4-2}

\usepackage{babel}
\usepackage{cleveref}

\newtheorem{myproposition}{Proposition}
\Crefname{myproposition}{Proposition}{Propositions}

\begin{document}
\cite{web:lang:stats}
\bibliography{myrefs}
\end{document}

myrefs.bib:

@misc{web:lang:stats,
  author = {W3Techs},
  title = {Usage Statistics of Content Languages for Websites},
  language = {English},
  year = {2017},
  note = {Last accessed 16 September 2017},
  url = {http://w3techs.com/technologies/overview/content_language/all}
}

If I put these two files into the same directory with nothing else in it (remove all temp files from previous compilations to make a clean experiment) and run

pdflatex min.tex && bibtex min.aux && pdflatex min.tex

I get

! TeX capacity exceeded, sorry [input stack size=5000].
\extrasenglish ->\extrasenglish 
                                \crefname {myproposition}{\MakeLowercase Pro...
l.12 \babel@aux{english}{}

Why? What did I do wrong?

Answer 1

You need babel because of the language field in the bib item. But you need to pass a language to babel. Best to add the language in the global options to \documentclass, so also cleveref will pick it.

\begin{filecontents*}{\jobname.bib}
@misc{web:lang:stats,
  author = {W3Techs},
  title = {Usage Statistics of Content Languages for Websites},
    language = {English},
  year = {2017},
  note = {Last accessed 16 September 2017},
  url = {http://w3techs.com/technologies/overview/content_language/all}
}
\end{filecontents*}

\documentclass[english]{revtex4-2}

\usepackage{babel}
\usepackage{cleveref}

\newtheorem{myproposition}{Proposition}
\Crefname{myproposition}{Proposition}{Propositions}

\begin{document}
\cite{web:lang:stats}
\bibliography{\jobname}
\end{document}

On the other hand, if you just use (American) English, you can remove the language field in the bib item(s) and not load babel.

Note. I used filecontents* with \jobname.bib just not to clobber my files. Use your own file and remove filecontents*.