Alex Kost <alezost@gmail.com> skribis:

> Hello, unlike other file system types, FAT volumes have short UUIDs,
> for example: "58D7-4FA5", but such an UUID cannot be used in an
> operating system declaration:
>
> (file-system
>   (device (uuid "58D7-4FA5"))
>   (title 'uuid)
>   (type "vfat")
>   ;; ...
>   )
>
> because (uuid "58D7-4FA5") errors.

That’s expected.  :-)  I’ve clarified this in 0767f6a: