Systemd-serial-console

serial-getty@ttyS0.service fails

[root@t4 ~]# systemctl status serial-getty@ttyS0.service
● serial-getty@ttyS0.service - Serial Getty on ttyS0
  Loaded: loaded (/usr/lib/systemd/system/serial-getty@.service; disabled; vendor preset: disabled)
  Active: inactive (dead)
    Docs: man:agetty(8)
          man:systemd-getty-generator(8)
          http://0pointer.de/blog/projects/serial-console.html
Jun 08 05:15:44 t4 systemd[1]: Stopped Serial Getty on ttyS0.
Jun 08 05:18:01 t4 systemd[1]: Dependency failed for Serial Getty on ttyS0.
Jun 08 05:18:01 t4 systemd[1]: serial-getty@ttyS0.service: Job serial-getty@ttyS0.service/start failed with result 'dependency'.

Manually start and enable:

systemctl start serial-getty@ttyS0.service
systemctl enable serial-getty@ttyS0.service

The fix was to enable the kernel CONFIG_FHANDLE feature.