I am trying to generate an image from a formula using LuaLaTeX and dvipng. Some of the formulas contain non-ascii characters like umlauts. When executing dvipng, I get errors like this:
This is dvipng 1.14 Copyright 2002-2010 Jan-Ake Larsson
kpathsea:make_tex: Invalid fontname `file:lmroman12-regular:script=latn;+trep;+tlig;', contains ':'
[1dvipng warning: font file:lmroman12-regular:script=latn;+trep;+tlig; at 400 dpi not found, characters will be left blank dvipng warning: unable to draw glyph 72, skipping dvipng warning: unable to draw glyph 65, skipping dvipng warning: unable to draw glyph 65, skipping dvipng warning: unable to draw glyph 65, skipping dvipng warning: unable to draw glyph 65, skipping dvipng warning: unable to draw glyph 76, skipping dvipng warning: unable to draw glyph 76, skipping dvipng warning: unable to draw glyph 76, skipping dvipng warning: unable to draw glyph 79, skipping dvipng warning: unable to draw glyph 79, skipping dvipng warning: unable to draw glyph 79, skipping dvipng warning: unable to draw glyph 79, skipping dvipng warning: unable to draw glyph 33, skipping kpathsea:make_tex: Invalid fontname `file:lmroman12-regular:script=latn;+trep;+tlig;', contains ':'
dvipng warning: font file:lmroman12-regular:script=latn;+trep;+tlig; at 400 dpi not found, characters will be left blank dvipng warning: unable to draw glyph 72, skipping dvipng warning: unable to draw glyph 65, skipping dvipng warning: unable to draw glyph 65, skipping dvipng warning: unable to draw glyph 65, skipping dvipng warning: unable to draw glyph 65, skipping dvipng warning: unable to draw glyph 76, skipping dvipng warning: unable to draw glyph 76, skipping dvipng warning: unable to draw glyph 76, skipping dvipng warning: unable to draw glyph 79, skipping dvipng warning: unable to draw glyph 79, skipping dvipng warning: unable to draw glyph 79, skipping dvipng warning: unable to draw glyph 79, skipping dvipng warning: unable to draw glyph 33, skipping ]
It complains about a missing font, but it definitely exists under ./share/texmf/fonts/opentype/public/lm/lmroman12-regular.otf.
The error occurs with the following MWE, compiled using lualatex --output-format=dvi test.tex
:
\documentclass{article}
\usepackage{amsmath}
\usepackage{fontspec} % if commented out, it works
\usepackage[active,textmath,displaymath]{preview}
\begin{document}
$\text{ä} < \text{ö}; ø\neq æ$
\end{document}
I'm using texlive-full (2016) on Debian testing. I would appreciate any pointers or explanations, I am stuck at this point, while researching the web for answers.
dvipng
does not support the extended font features of LuaTeX../
?