New comment by svenper on void-packages repository

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

Comment:
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.