I installed the missing package and the Fira font family. The problem is, now, that I cannot use LuaLaTeX to compile, only xetex and pdflatex. The issue is no more related with the metropolis theme. In fact, with the simple document test.tex
\documentclass{article}
\begin{document}
This is a test of the article
\end{document}
The output of lualatex test.tex
is this, with the last lines
24 preloaded fonts
warning (pdf backend): no pages of output.
Transcript written on lualatex.log.
mktexfmt [INFO]: log file copied to: /home/panbroggi/.texlive/texmf-var/web2c/luatex/lualatex.log
mktexfmt [INFO]: /home/panbroggi/.texlive/texmf-var/web2c/luatex/lualatex.fmt installed.
mktexfmt [INFO]: disabled formats: 6
mktexfmt [INFO]: successfully rebuilt formats: 1
mktexfmt [INFO]: not selected formats: 41
mktexfmt [INFO]: total formats: 48
mktexfmt [INFO]: exiting with status 0
---! lualatex.fmt was written by luatex
(Fatal format file error; I'm stymied)
I also tried to renew the ~/.texlive
folder with
mv ~/.texlive ~/.texlive-old
fmtutil-user -all
sudo fmtutil-sys -all
sudo texhash
but nothing changed.