# Change hyphenation rules in polyglossia

I found that there are other hyphenation rules in my language package (https://ctan.org/tex-archive/language/hyphenation/ukrhyph). How can I activate not default hyphen rules? By default Ukrainian language settings use very liberal hyphenation rules.

\documentclass{article}

\usepackage{polyglossia}
\setmainlanguage{ukrainian}

\setmainfont{Noto Serif}
\begin{document}
\parbox{0em}{хімічний}
\end{document}


Produces хі-мі-чний, but with ukrhypmt.tex should produce хі-міч-ний

• The files on CTAN provide for hyphenation with T2A encoded fonts, so they're unsuitable for Unicode based fonts. It is possible that the current patterns for Unicode have mistakes. There is a TUG mailing list for problems with hyphenation: tug.org/mailman/listinfo/tex-hyphen. Anyway, the same hyphenation is obtained with pdflatex and T2A encoding. – egreg Nov 30 '18 at 21:25
• \showhyphens{хімічний} is a better way to see hyphen points in general, the 0 width parbox would not work in xetex for example as xetex like pdftex does not hyphenate the first word. You can use \hyphenation{хі-міч-ний} to specify that rule. – David Carlisle Nov 30 '18 at 21:26

To update the LuaTeX hyphenation patterns you need to replace the file located at /usr/local/texlive/2017/texmf-dist/tex/generic/hyph-utf8/patterns/txt/hyph-uk.pat.txt
% File: ukrhypsm.tex THIS LINE SHOULD BE REMOVED