[XeTeX] showhyphens and fontspec

[Pablo Rodríguez]

For some reason unknown to me, \showhyphens is not able to display
hyphens when \setromanfont is selected.

\documentclass{article}
\usepackage[spanish]{babel}
\usepackage{fontspec}
\setromanfont{Palatino Linotype}
\begin{document}
\showhyphens{semana}
\end{document}

If you comment the fourth line out, hyphens will be displayed.

Is it possible to solve this?



Pablo