[brianush1]

Posix file names can be any sequence of bytes other than '/' and 0

[hamburglar]

I guess that's true. I suspect the support for non-UTF8 names in modern tooling is very, very spotty, given how many config files and file formats that refer to other files use UTF-8 themselves. E.g. can you refer to one of these names in an nginx config? (just an example; I have no idea if its config is UTF-8 or not)

[benibela]

I have a collection of non-utf8 and other problematic files to test such tools:

https://github.com/benibela/nasty-files

You probably cannot clone the repo on Windows. It works well on Linux. But in KDE you could not delete it after checkout

[tyingq]

Also, filenames with one or more newlines bork a lot of Linux software.

[masklinn]

And Windows file names can include unpaired surrogates, which are not allowed in UTF8 (that’s why WTF8 exists).