# Polyglossia setotherlanguage conflicts with tikz library quotes

When I use tikz with the quotes package in a graph environment to add a label to an edge (as I found out here: Label on edges with tikz-graph) I get problems as soon as I specify an otherlangue with polyglossia.

I've seen other people reporting similar issues with the babel package: problems with tikz and arabi package and Adding a TikZ figure to a document. In both cases the solution was to switch to English but that does not help in this case.

My MWE is:

\documentclass{article}
\usepackage{polyglossia}
\setmainlanguage{english}
\setotherlanguage{german}
\usepackage{tikz}
\usetikzlibrary{quotes}
\usetikzlibrary{graphs}

\begin{document}
\begin{english}
\begin{tikzpicture}
\graph {
"A" -- "B" [> "some label"]
};
\end{tikzpicture}
\end{english}
\end{document}


The output is:

! Package pgfkeys Error: I do not know the key '/tikz/"{some label}"' and I am
going to ignore it. Perhaps you misspelled it.

See the pgfkeys package documentation for explanation.
Type  H <return>  for immediate help.
...

l.14       }
;
?


The XeLaTeX version is: XeTeX 3.14159265-2.6-0.99999 (TeX Live 2019/dev/Debian)

pgf version is: 3.1.1

## 1 Answer

According to what I find adding \usetikzlibrary{babel} fixes it. I use an updated TeXLive 2019 installation with pgf v3.1.5 and checked both lualatex and xelatex.

\documentclass{article}
\usepackage{polyglossia}
\setmainlanguage{english}
\setotherlanguage{german}
\usepackage{tikz}
\usetikzlibrary{quotes}
\usetikzlibrary{graphs}
\usetikzlibrary{babel}

\begin{document}
\begin{english}
\begin{tikzpicture}
\graph {
"A" -- "B" [> "some label"]
};
\end{tikzpicture}
\end{english}
\end{document}