What should the home directory of a non-interactive user account be set to?

[root@Acheron ~]# systemctl status shadow
● 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 Tue 2019-05-14 13:59:34 EDT; 1s ago
  Process: 25502 ExecStart=/bin/sh -c /usr/bin/pwck -r || r=1; /usr/bin/grpck -r && exit $r (code=exited, status=1/FAILURE)
 Main PID: 25502 (code=exited, status=1/FAILURE)

May 14 13:59:34 Acheron systemd[1]: Started Verify integrity of password and group files.
May 14 13:59:34 Acheron sh[25502]: user 'netdata': directory '/home/netdata' does not exist
May 14 13:59:34 Acheron sh[25502]: pwck: no changes
May 14 13:59:34 Acheron systemd[1]: shadow.service: Main process exited, code=exited, status=1/FAILURE
May 14 13:59:34 Acheron systemd[1]: shadow.service: Failed with result 'exit-code'.

This user should not have a home directory. I'd like to update its entry in /etc/passwd to remove the home directory. I could edit this file directly, but that seems unsafe. Is there a better way?

Looking at other entries in /etc/passwd it seems that users "without a home directory" actually just have their home directory set to /.

I used usermod -d / netdata to update the user's home directory to match.