I recently installed version openldap-2.4.23 on one of our Degreeworks servers as root. During the ./configure piece, I had to disable slapd because it complained about a BDB database.
Berkeley DB is software from Oracle (formerly Sleepycat) that is used for creating and storing LDAP databases in OpenLDAP with the back-bdb and back-hdb backends. You probably need to download and build BDB before you build OpenLDAP.
--Quanah -- Quanah Gibson-Mount Sr. Member of Technical Staff Zimbra, Inc A Division of VMware, Inc. -------------------- Zimbra :: the leader in open source messaging and collaboration