I just switched to Libertinus Math and now have a problem with an \underbrace! While using Latin Modern as math font I get the expected result:
\documentclass{article}
\usepackage{amsmath}
\usepackage{mathtools}
\usepackage[
math-style=ISO,
bold-style=ISO,
partial=upright,
nabla=upright
]{unicode-math}
\usepackage{libertine}
%\setmathfont{Libertinus Math}
\usepackage{microtype}
\begin{document}
FAT-16: \[\underbrace{\text{16-Bit}}_{\mathclap{\text{Größe einer Adresse (für das Speichern der Dateien)}}}\text{-Dateisystem}\]
\end{document}
After switching to Libertinus Math the \underbrace has a wrong size:
Any idea how to fix it?
(ed.) minimal example
\documentclass{article}
\usepackage{unicode-math}
\setmathfont{Libertinus Math}
\begin{document}
\[\underbrace{z}_{a}\]
\[\underbrace{zz}_{a}\]
\[\underbrace{zzz}_{a}\]
\[\underbrace{zzzz}_{a}\]
\[\underbrace{zzzzz}_{a}\]
\[\underbrace{zzzzzz}_{a}\]
\[\underbrace{zzzzzzz}_{a}\]
\end{document}
% Local Variables:
% TeX-engine: luatex
% End:
Surprisingly, xelatex exhibits different output which fails less often:
\documentclass{article}
\usepackage{unicode-math}
\setmathfont{Libertinus Math}
\begin{document}
\[\underbrace{z}_{a}\]
\[\underbrace{zz}_{a}\]
\[\underbrace{zzz}_{a}\]
\[\underbrace{zzzz}_{a}\]
\[\underbrace{zzzzz}_{a}\]
\[\underbrace{zzzzzz}_{a}\]
\[\underbrace{zzzzzzz}_{a}\]
\end{document}
% Local Variables:
% TeX-engine: xetex
% End:
Here is using with the Libertinus as in TeXLive 2018 current pretest, updated. Things are much better but still a bit strange for zzz. In images below, maybe I have one more lines, because I extended mwe in the meantime.
With xetex at left and luatex at right:






zzzlook sub-optimal. Loading or not mathtools changes nothing. – Mar 25 '18 at 12:45