Installation of a new machine breaks when the sasl and ldap use flags are both set, since the packages openldap and cyrus-sasl depend on each other. It is necessary to emerge openldap first with temporarily disabled sasl use flag, then emerge cyrus-sasl and finally reemerging openldap again, this time with sasl use flag set.
So you know the workaround. Unfortunately still no Portage version out that deals with this gracefully. *** This bug has been marked as a duplicate of 32394 ***