ls doesn't gracefully handle all errors

[pixelb]

$ ./coreutils ls --version
ls (uutils coreutils) 0.7.0
$ ./coreutils ls /bin/ls/foo
ls: unknown io error: '/bin/ls/foo', 'Os { code: 20, kind: NotADirectory, message: "Not a directory" }'

[oech3]

This project cannot just show OS provided error message to align error messages at many platforms. So we duplicate many error messages on Linux to this repo and increase size of binary, and manually map error code to them.

This is why we have such kind of bugs...