luatex problem with file with umlauts on windows 10

[Ulrike Fischer]

Am Sat, 25 Apr 2020 23:52:25 +0900 schrieb Akira Kakuto:

Dear Akira,
> 
> lua part is not utf-8 in TeX Live Windows. Please try:

After removing the two comments (--) it works fine, both in miktex
and texlive.

So chgstrcp.utf8tosyscp(file) is the secret. 

Why isn't it enabled by default? (e.g. depending on
command_line_encoding)?

(Currently the file search in expl3 is broken because of this, so
I'm considering our options).

-- 
Ulrike Fischer 
https://www.troubleshooting-tex.de/