New comment by svenper on void-packages repository

https://github.com/void-linux/void-packages/issues/11963#issuecomment-612472624

Comment:
Whenever the log mentions METAFONT, it's not using OpenType or TrueType fonts normally used with XeTeX. Usually it can't find the font, but the Path option to fontspec can work around this.

If a system update is involved, have you tried regenerating formats etc?
```
sudo mktexlsr
sudo fmtutil --sys --all
sudo updmap --sys --syncwithtrees
sudo updmap --sys
```

My impressions:

```
\setCJKmainfont{rmplus}[Script=CJK, Language=Japanese]{rounded-mplus-1p-regular}
```
 looks wrong, there should be only one font name, i.e. one of
```
\setCJKmainfont[Script=CJK, Language=Japanese]{‹name›}
\setCJKmainfont{‹name›}[Script=CJK, Language=Japanese]
```

and there is no need for 
```
\CJKfamily{rmplus}
```
since script should be detected automatically by unicode range.

This works for me:™

```
\documentclass{article}
\usepackage{fontspec,xeCJK}
\setmainfont{SourceSerifPro-Regular.otf}[Path=/tmp/]
\setCJKmainfont{SourceHanSerif-Regular.otf}[Path=/tmp/,Script=CJK,Language=Japanese]
\begin{document}
test テスト
\end{document}
```

I would recommend asking on [tex.stackexchange.com](https://tex.stackexchange.com), that's where the TeX devs hang out.