Dear Maintainer,

*** Reporter, please consider answering these questions, where appropriate ***

   * What led up to the situation?
   * What exactly did you do (or not do) that was effective (or
     ineffective)?
   * What was the outcome of this action?
   * What outcome did you expect instead?

Dear Maintainer,

On Debian 13 (Trixie), Timeshift 24.06.6-2 does not correctly detect
a multi-device BTRFS RAID1 filesystem in the GTK interface.

The system has a BTRFS filesystem using:

  /dev/sda5
  /dev/nvme0n1p5

Both devices belong to the same BTRFS filesystem (UUID
0c253f05-4e21-4d66-b7d3-b0aeeeed7155).

BTRFS reports Data, Metadata and System as RAID1, with both devices
participating and no missing devices.

The filesystem has approximately 184 GiB free according to df.

The problem is that the Timeshift GTK interface does not show either
/dev/sda5 or /dev/nvme0n1p5 as a selectable BTRFS snapshot device and
reports insufficient disk space.

However, the Timeshift command-line interface correctly detects the
devices:

  $ sudo timeshift --list-devices

  1    >  /dev/sda5        203.2 GB  btrfs
  2    >  /dev/nvme0n1p5   219.2 GB  btrfs

More importantly, the CLI can successfully create a BTRFS snapshot:

  $ sudo timeshift --create --comments "Test" --tags D

It reports:

  Using system disk as snapshot device for creating snapshots in BTRFS mode
  Saving to device: /dev/sda5
  BTRFS Snapshot saved successfully

The snapshot is actually created as a BTRFS subvolume.

Therefore the BTRFS filesystem itself is working correctly and has
sufficient free space. The problem appears to be specific to the
Timeshift GTK interface, either in BTRFS device detection or in its
free-space check for multi-device BTRFS RAID1 filesystems.

Expected behavior:
The GTK interface should detect the existing BTRFS filesystem and
allow it to be selected as the snapshot location, without reporting
that the disk is out of space.

Actual behavior:
Neither BTRFS device is offered by the GTK interface and it reports
insufficient disk space, despite approximately 184 GiB being available.

The command-line interface works correctly with the same filesystem.

Regards,