Dear Maintainer,

timeshift is working with btrfs, when it is not encrypted with LUKS and sysvinit.
But with an encrypted drive, timeshift does work not with my BTRFS-filesystem
with sysvinit. There is only a warning, that the system-drive is not found.

Here some Infos about the system:

~# cat /etc/fstab
UUID=779a1789-d53f-4882-bdcc-36e142fc482a / btrfs rw,noatime,subvol=@ 0 1
UUID=cbc12706-9f45-452f-9d0d-4cfef99e8042 /boot ext4 defaults,noatime 0 2
UUID=779a1789-d53f-4882-bdcc-36e142fc482a /home btrfs rw,noatime,subvol=@home 0 2
UUID=779a1789-d53f-4882-bdcc-36e142fc482a /.snapshots btrfs rw,noatime,subvol=@snapshots 0 2
tmpfs /tmp tmpfs defaults,nosuid,nodev 0 0

~# btrfs subvolume list /
ID 256 gen 8874 top level 5 path @
ID 262 gen 8765 top level 5 path @home
ID 263 gen 8752 top level 5 path @snapshots

~# mount
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,nosuid,relatime,size=1993068k,nr_inodes=498267,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=600,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,nodev,noexec,relatime,size=402388k,mode=755)
/dev/mapper/sda2_crypt on / type btrfs (rw,noatime,space_cache,subvolid=256,subvol=/@)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
securityfs on /sys/kernel/security type securityfs (rw,relatime)
pstore on /sys/fs/pstore type pstore (rw,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,noexec,relatime,size=804760k)
/dev/sda1 on /boot type ext4 (rw,noatime)
/dev/mapper/sda2_crypt on /home type btrfs (rw,noatime,space_cache,subvolid=262,subvol=/@home)
/dev/mapper/sda2_crypt on /.snapshots type btrfs (rw,noatime,space_cache,subvolid=263,subvol=/@snapshots)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,relatime)
cgroup2 on /sys/fs/cgroup type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate)
tmpfs on /run/user/0 type tmpfs (rw,nosuid,nodev,relatime,size=402384k,nr_inodes=100596,mode=700)
tmpfs on /run/user/1000 type tmpfs (rw,nosuid,nodev,relatime,size=402384k,nr_inodes=100596,mode=700,uid=1000,gid=1000)


~# timeshift --check
E: System disk not found!

~# timeshift --debug
D: Main()
D:
D: Running Timeshift v20.11.1
D:
D: Session log file: /var/log/timeshift/2023-04-13_04-55-20_.log
D: Distribution: debian "11"
D: DIST_ID: debian
D: Main: check_dependencies()
D: Main: add_default_exclude_entries()
D: Main: add_default_exclude_entries(): exit
D: update_partitions()
D: df -T -B1
D: Device: get_disk_space_using_df(): 1
D: Device: get_mounted_filesystems_using_mtab(): 1
D: Device: get_filesystems(): 5
D: partition list updated
D: detect_system_devices()
D: /boot is mapped to device: /dev/sda1, UUID=cbc12706-9f45-452f-9d0d-4cfef99e8042
D: Searching subvolume for system at path: /
D: Found subvolume: @, on device:
D: Found subvolume: @home, on device:
D: Found subvolume: @snapshots, on device:
D: Users: tom root
D: Encrypted home users:
D: Encrypted home dirs:

D: Encrypted private dirs:

D: Main: load_app_config()
App config loaded: /etc/timeshift/timeshift.json
D: IconManager: init()
D: bin_path: /usr/bin/timeshift
D: found images directory: /usr/share/timeshift/images
D: Main(): ok
D: AppConsole: parse_arguments()
D: Main: initialize_repo()
D: backup_uuid=
D: backup_parent_uuid=
D: Setting snapshot device from config file
D: Main: initialize_repo(): exit
D: AppConsole: start_application()
D: exit_app()
D: Main: save_app_config()
D: SnapshotRepo: available()
D: device is null
D: is_available: false
App config saved: /etc/timeshift/timeshift.json
D: unmount_target_device()
D: clean_logs()
D: rm -rf '/tmp/8N47lEDL'

Control: severity -1 normal
X-Debbugs-CC: news@ambag.es
sysvinit/runit does not work.
sysvinit.
filesystem
found.

Hi,

Since sysvinit is not enabled by default in Debian, I do not consider this
bug as release-critical. Downgrading the bug severity to "normal".

Frankly speaking, I myself do not use any of btrfs, LUKS or sysvinit at all,
so I have no capability in debugging the bug. You are encouraged to forward
your setup and problem to timeshift upstream.

Thanks,
Boyuan Yang
rw,noatime,subvol=@home 0 2
rw,noatime,subvol=@snapshots 0 2
(rw,nosuid,relatime,size=1993068k,nr_inodes=498267,mode=755)
(rw,nosuid,noexec,relatime,gid=5,mode=600,ptmxmode=000)
(rw,nosuid,nodev,noexec,relatime,size=402388k,mode=755)
(rw,noatime,space_cache,subvolid=256,subvol=/@)
(rw,nosuid,nodev,noexec,relatime,size=804760k)
(rw,noatime,space_cache,subvolid=262,subvol=/@home)
(rw,noatime,space_cache,subvolid=263,subvol=/@snapshots)
(rw,nosuid,nodev,noexec,relatime,nsdelegate)
(rw,nosuid,nodev,relatime,size=402384k,nr_inodes=100596,mode=700)
(rw,nosuid,nodev,relatime,size=402384k,nr_inodes=100596,mode=700,uid=1000,gi
d=1000)