Dear list,

I’ve been tackling a similar problem as in [1]:

$ cat minimal.tex

   \documentclass{minimal}
   \usepackage{fontspec}
   \setmainfont{Latin Modern Sans}
   \begin{document}
   Hello
   \end{document}

$ guix environment --container --ad-hoc texlive texlive-latex-fontspec texlive-lm
[env]$ xelatex minimal

   (/gnu/store/ar2lrskw5mbqyc8k7ai3i7p5ig6fdkp0-texlive-texmf-20180414/share/texmf
   -dist/tex/latex/fontspec/fontspec.cfg)))kpathsea:make_tex: Invalid filename `Latin Modern Sans', contains ' '

   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
   !
   ! fontspec error: "font-not-found"
   ! 
   ! The font "Latin Modern Sans" cannot be found.
   ! 
   ! See the fontspec documentation for further information.
   ! 
   ! For immediate help type H <return>.
   !...............................................  
                                                   
   l.3 \setmainfont{Latin Modern Sans}

Actually, it started with me trying to obtain a pdf output with `pandoc
--pdf-engine=xelatex` from a markdown file. This returns a different
error, albeit seemingly related: lmodern not found. So the issue looks
deeper than the space in the font name.

For an environment without `--container`, `fc-match` returns no match,
even after `fc-cache -f`.

Any hint will be appreciated.

WŻ

[1]: https://github.com/NixOS/nixpkgs/issues/24485