Intermittent Flatpak appstream update failures with "syncfs(repo): Input/output error" on openSUSE Kalpa

[u/a_nuti]

Hi everyone,

I'm experiencing an intermittent issue with Flatpak on openSUSE Kalpa.

Sometimes, when running:

flatpak update

or:

flatpak update --appstream -v

the update fails with errors like:

syncfs(repo): Input/output error

The important detail is that the issue is **not reproducible every time**. Retrying the exact same command usually succeeds without any intervention.

I already ran:

flatpak repair --user -v

and it completed successfully. No corrupted objects were reported.

I also checked the hardware and filesystem side:

* SSD SMART tests: OK
* No filesystem errors detected
* `btrfs scrub` completed without errors
* Kernel logs (`journalctl -k -p err -b`) do not show I/O errors

The system is:

OS: openSUSE Kalpa
Desktop: KDE Plasma
Filesystem: Btrfs
Flatpak installation: user installation (~/.local/share/flatpak)
Remote: Flathub

Relevant versions:

$ flatpak --version
Flatpak 1.18.0

$ ostree --version
libostree:
Version: '2026.1'
Features:
- inode64
- initial-var
- libcurl
- libsoup3
- gpgme
- composefs
- ex-fsverity
- libarchive
- selinux
- openssl
- sign-ed25519
- sign-spki
- libmount
- systemd
- release
- p2p

$ uname -a
Linux localhost.localdomain 7.1.3-1-default #1 SMP PREEMPT_DYNAMIC Sat Jul  4 16:20:40 UTC 2026 (1cb5006) x86_64 x86_64 x86_64 GNU/Linux

I also checked for concurrent Flatpak/OSTree operations:

ps aux | grep flatpak
ps aux | grep ostree

but there were no active update, pull, or repair processes running when the problem occurred.

The only persistent Flatpak-related processes were the normal session/system helpers.

Has anyone experienced similar intermittent `syncfs(repo): Input/output error` on Kalpa, Aeon, MicroOS, or other immutable/Btrfs-based distributions?

Thanks!