The necessary ldap schema files to run kerberos with the ldap backend are not installed even when the ldap option is set in config. The files can be found under src/plugins/kdb/ldap/libkdb_ldap/ in the work/krb5.*/ directory, but are not installed as part of the make install process. According to most documentation they should be installed in the share/doc/ directory for implementation by sysadmin when/where required.
Fix synopsis and assign.
ls /usr/local/share/krb5/|grep schema kerberos.schema seems solved.
Thanks for verifying.