$ systemctl status shadow.service

● shadow.service - Verify integrity of password and group files
   Loaded: loaded (/usr/lib/systemd/system/shadow.service; static; vendor preset: disabled)
   Active: failed (Result: exit-code) since Thu 2015-12-10 12:02:16 IRST; 45s ago
  Process: 13692 ExecStart=/usr/bin/pwck -r (code=exited, status=2)
 Main PID: 13692 (code=exited, status=2)

Dec 10 12:02:16 Box systemd[1]: Starting Verify integrity of password and group files...
Dec 10 12:02:16 Box pwck[13692]: user 'prey': directory '/home/prey' does not exist
Dec 10 12:02:16 Box pwck[13692]: pwck: no changes
Dec 10 12:02:16 Box systemd[1]: shadow.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
Dec 10 12:02:16 Box systemd[1]: Failed to start Verify integrity of password and group files.
Dec 10 12:02:16 Box systemd[1]: shadow.service: Unit entered failed state.
Dec 10 12:02:16 Box systemd[1]: shadow.service: Failed with result 'exit-code'.