[Bug 56267] New: Cannot create wineprefix on loop device ?

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56267

Bug ID: 56267
           Summary: Cannot create wineprefix on loop device ?
           Product: Wine
           Version: 9.0
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: -unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 75983
  --> https://bugs.winehq.org/attachment.cgi?id=75983
error logs

Hello, I have created a loop device to store my wineprefixes in. However, wine
does not work with it.

How I created it :

```
dd if=/dev/zero of=loop.img bs=100M count=50
udisksctl loop-setup -f loop.img
```

Then formatted it as NTFS using gnome-disks.

It is properly detected as NTFS, I can copy-paste files in GNOME Files to and
from the mounted loop device. And yet wine apparently cannot create a
wineprefix on it.

wine --version returns 9.0 (Staging).

I checked the permissions for the loopdevice/mounted partition and it was fine
too.
Do note that I am running wine inside of a toolbox container, but just to rule
out that this wasn't a Wine 9 or toolbox container issue, I downloaded
org.winehq.Wine stable 23.08 from flathub, gave it --filesystem=host
permission, changed the envvar for WINEPREFIX to /run/media/$USER/USBa and it
gave me the same exact error, USBa is a physical USB drive formatted as exFAT.

[Bug 56267] Cannot create wineprefix on loop device ?

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56267

--- Comment #1 from Alexandre Julliard  ---
Wine requires a Unix filesystem for prefixes, NTFS or FAT are not going to
work.