Unable to handle rsync error

[horror-proton]

When starting psd.service, rsync failed to sync config due to tmpfs out of space. But it kept running and cause data loss.

Expected behavior: psd should roll back the transaction and call for help from user if rsync did dot return zero.

May 09 18:50:17 archlinux systemd[637]: Starting Timed resync...
May 09 18:50:18 archlinux profile-sync-daemon[9450]: rsync: [receiver] write failed on "/run/user/1000/psd/arch-google-chrome/Default/Service Worker/CacheStorage/...": No space left on device (28)
May 09 18:50:18 archlinux profile-sync-daemon[9450]: rsync error: error in file IO (code 11) at receiver.c(380) [receiver=3.2.7]
May 09 18:50:18 archlinux profile-sync-daemon[9449]: rsync: [sender] write error: Broken pipe (32)
May 09 18:50:18 archlinux profile-sync-daemon[9449]: rsync error: error in file IO (code 11) at io.c(848) [sender=3.2.7]
May 09 18:50:18 archlinux profile-sync-daemon[9411]: google-chrome sync successful
May 09 18:50:19 archlinux systemd[637]: Finished Timed resync.