"Cannot determine realm for host" when system doesn't have full hostname
Binary package hint: libpam-heimdal
pam heimdal reports the following error when attempting to log in:
credential verification failed: Cannot determine realm for host
This happens if the hostname of the system is not an fqdn (`hostname` returns 'foo' rather than 'foo.example.com'). Fortunately or not, not having an fqdn hostname appears to be the default on an Ubuntu install.
I would say this is not a bug, except that libpam-krb5 handles this situation just fine.