eurosym in Pandoc seems to be incompatible with hyperref

[harriott]

• Windows 10 version 1703, MiKTeX 2.9.6300 64-bit, pandoc v1.19.2.1.
• Arch linux 4.11.9-1, texlive-bin 2016.41290-12, pandoc 1.19.2.1-90.

eurosym.md contains just:

# 2€
2€

pandoc eurosym.md -o eurosym.pdf --latex-engine=xelatex returns variants of:

! Improper alphabetic constant.
<to be read again>
                   \euro
l.70 \section{2\euro{}}

pandoc.exe: Error producing PDF

Further details: pandoc convert to pdf fails when € is in a header.

[mb21]

could not reproduce on macOS with pandoc 1.19.2.1 and XeTeX 3.14159265-2.6-0.99996 (TeX Live 2016)

have you modified your default template?

[harriott]

mb21, no (as elaborated on StackOverflow), I've used the latest jgm default.latex.

[jgm]

The second answer here is illuminating on what the error message means: https://tex.stackexchange.com/questions/64900/improper-alphabetic-constant Not sure yet how to fix this in pandoc.

[jgm]

Note that this works fine with --latex-engine=pdflatex. The difference is that, when pdflatex is used, we have \usepackage{eurosym} while with xelatex, we have \newcommand{\euro}{€} in the default template.

[jgm]

Minimal case that fails for me using xelatex:

\documentclass[]{article}
\usepackage{unicode-math}
\newcommand{\euro}{€}

\usepackage[unicode=true]{hyperref}

\begin{document}

\hypertarget{section}{
\section{2\euro{}}\label{section}
}

\end{document}

Note that if you comment out the unicodemath part, OR if you remove hyperref and the hyperref specific commands, it compiles successfully. So it's the combination of the custom \euro macro with BOTH unicodemath and hyperref that seems to cause the problem.

[adunning]

This can be fixed by dropping the \euro command and the two associated lines from the template, and writing € directly. It's already handled through the textcomp package (part of the core LaTeX distribution), which is automatically loaded when using the Pandoc template under pdfLaTeX via the upquote package. (To prevent errors, either the conditional loading of the upquote package in the template should be removed, or textcomp should be called directly with pdfLaTeX.)

The following produces an identical PDF under any of the three LaTeX engines:

\documentclass{article}
\usepackage{lmodern}
\usepackage{ifxetex,ifluatex}
\ifnum 0\ifxetex 1\fi\ifluatex 1\fi=0 % if pdftex
  \usepackage[T1]{fontenc}
  \usepackage[utf8]{inputenc}
\else % if luatex or xelatex
  \usepackage{unicode-math}
  \defaultfontfeatures{Ligatures=TeX,Scale=MatchLowercase}
\fi
\usepackage{upquote}
\usepackage{hyperref}

\begin{document}

\hypertarget{section}{
\section{2€}\label{section}
}

\end{document}