Translation not working when using siunitx + glossaries + polyglossia + xindy + LuaLaTeX

Question

I'm trying to move to a modern LaTeX setup, by using LuaLaTex, polyglossia, glossaries + xindy.

When I create a German document with a glossary, the title of the glossary correctly changes to "Glossar", the German translation of glossary.

If I add \usepackage{siunitx} to load siunitx, translation will break - the title of the glossary will change back to "Glossary". Example (compile with lualatex + makeglossaries + lualatex):

\documentclass{article}

\usepackage{fontspec}
\usepackage{polyglossia}
\setdefaultlanguage{german}

\usepackage{siunitx}

\usepackage[xindy]{glossaries}
\makeglossaries

\newglossaryentry{a}{name = ä, description = A Umlaut}

\begin{document}
\printglossaries
Testing the entry: \gls{a}.
\end{document}

Removing the line to load siunitx will fix this problem, as will loading translator explicity (before loading siunitx) with \usepackage[german]{translator}.

I believe this happens because siunitx.sty loads translator without any language options with \RequirePackage { translator }.

I'm not an expert, so I'm not sure if this behaviour is to be expected. But from a user's perspective, it seems siunitx breaks translation. Is this a bug? If so, in which package, and who should I report this to?

---

One other thing: xindy will report Cannot locate xindy module for language german in codepage utf8, and will switch to language general, unless I add \GlsSetXdyCodePage{duden-utf8}. Is this a bug?

Answer 1

The glossaries package will use translator if loaded for translating strings. The translator package requires that the language name is given as a global (class) option (which is usual babel 'best practice'). Unfortunately, polyglossia doesn't use this method as standard, but it will work happily. Try

\documentclass[german]{article}

\usepackage{polyglossia}
\setdefaultlanguage{german}
\usepackage{translator}
\usepackage[xindy]{glossaries}
\makeglossaries
\usedictionary{german}
\newglossaryentry{a}{name = ä, description = A Umlaut}

\begin{document}
\printglossaries
Testing the entry: \gls{a}.
\end{document}

Note that this is really not the fault of siunitx beyond the fact it loads translator if available: you'd see the same with any package loading translator or indeed if like in my demo you load it directly.

Answer 2

You can explicitly load the glossaries-polyglossia package to fix the problem:

\documentclass{article}

\usepackage{fontspec}
\usepackage{polyglossia}
\setdefaultlanguage{german}

\usepackage{siunitx}

\usepackage[xindy]{glossaries}
\usepackage{glossaries-polyglossia}
\makeglossaries

\newglossaryentry{a}{name = ä, description = A Umlaut}

\begin{document}
\printglossaries
Testing the entry: \gls{a}.
\end{document}

In some cases, you may also need to use the translate=false package option:

\documentclass{article}

\usepackage{fontspec}
\usepackage{polyglossia}
\setdefaultlanguage{german}

\usepackage{siunitx}

\usepackage[xindy,translate=false]{glossaries}
\usepackage{glossaries-polyglossia}
\makeglossaries

\newglossaryentry{a}{name = ä, description = A Umlaut}

\begin{document}
\printglossaries
Testing the entry: \gls{a}.
\end{document}

Although this particular example seems to work without it.