Following the code used both here and here, using \hyphenrules
should inform polyglossia
about breaking points within a word. The following code does not break the word in question. Why not? What can I do? I'm using version 1.43 of polyglossia
.
\documentclass{article}
\usepackage{polyglossia}
\setmainlanguage{english}
\begin{hyphenrules}{english}
\hyphenation{de-ri-va-tio-nal}
\hyphenation{non-de-ri-va-tio-nal}
\end{hyphenrules}
\begin{document}
\parbox{0pt}{\hspace{0pt}non-derivational}
\end{document}
nonderivational
you get all the break points you wish for.