From Fedora Project Wiki

  • Kerberos Problems:

Kerberos has stored the CC file in /tmp since it was invented. Certain priv apps like rpc.gssd and sssd want to use the users /tmp for reading or creation of those files.

If the user has a different /tmp then rpc.gssd or sssd, these tools will fail. I am working with the sssd/kerberos teams to move the default location for credential cache files to /run/user/USERNAME/ Perhaps a feature of Fedora 18.

Replay Cache files are currently stored in /var/tmp so this should not be a problem.