Comment # 1 on bug 1085086 from Mario Goppold

And this config bring the systemd-tmpfiles service into failed state:

  systemd-tmpfiles[16308]: [/usr/lib/tmpfiles.d/systemd.conf:19] Unknown user
'systemd-network'.
  systemd[1]: systemd-tmpfiles-clean.service: Main process exited, code=exited, 
  status=1/FAILURE
  systemd[1]: Failed to start Cleanup of Temporary Directories.
  systemd[1]: systemd-tmpfiles-clean.service: Unit entered failed state.
  systemd[1]: systemd-tmpfiles-clean.service: Failed with result 'exit-code'.