michal, what do you mean by "spaces aren't recognized by tex4ht"? is there more to do here?

posted also at

https://tex.stackexchange.com/questions/426730/make4ht-crashes-error-code-256-when-using-arev-with-bold-font

TL 2017

This might be known issue, but did not see it googling. I sort of remember seeing this before, but I could be wrong. So thought to post this just in case. If this is known, will close this.

This MWE
----------------------
\documentclass[11pt]{article}%
\usepackage{amsmath}
\usepackage{arev}

\begin{document}
\textbf{test}.
\end{document}
----------------

When compiled using make4ht --lua foo.tex causes

--- error --- Improper file `favb8r.htf'
Make4ht: Fatal error. Command tex4ht returned exit code 256
Using TL 2017 in cygwin:

>ls -l /usr/local/texlive/2017/texmf-dist/tex4ht/ht-fonts/alias/arev/favb8r.h

-rw-r--r-- 1 me None 44 Nov 25 2016 favb8r.htf

>cat /usr/local/texlive/2017/texmf-dist/tex4ht/ht-fonts/alias/arev/favb8r.htf

.favb8r
htfcss: favb8r font-weight: bold;

>

May be the extra empty lines in the file favb8r.htf is the cause?

More complete console ouptput:

.....
Output written on foo2.dvi (1 page, 10520 bytes).
Transcript written on foo2.log.
Make4ht: tex4ht "foo2.dvi"
----------------------------
tex4ht.c (2012-07-25-19:36 kpathsea)
tex4ht foo2.dvi
(/usr/local/texlive/2017/texmf-dist/tex4ht/base/unix/tex4ht.env)
(/usr/local/texlive/2017/texmf-dist/tex4ht/ht-fonts/iso8859/1/charset/unicode.4hf)
(/usr/local/texlive/2017/texmf-dist/fonts/tfm/public/arev/favb8r.tfm)
(/usr/local/texlive/2017/texmf-dist/tex4ht/ht-fonts/alias/arev/favb8r.htf)
--- error --- Improper file `favb8r.htf'
Make4ht: Fatal error. Command tex4ht returned exit code 256

The error do not show up when using make4ht foo.tex. Only when adding --lua does the error show up.

Thanks,
--Nasser