developerz yel # emerge --update \=net-nds/openldap-2.3.24-r1
Calculating dependencies... done!
>>> Emerging (1 of 1) net-nds/openldap-2.3.24-r1 to /
>>> checking ebuild checksums ;-)
>>> checking auxfile checksums ;-)
>>> checking miscfile checksums ;-)
>>> checking openldap-2.3.24.tgz ;-)
 *
 * Scanning datadir(s) from slapd.conf and
 * the default installdir for Versiontags
 * (/var/lib/openldap-data may appear twice)
 *
 * - Checking /var/lib/openldap-data...
 *    Found Versiontag in /var/lib/openldap-data
 *    Versiontag doesn't match current major release!
 *    Versiontag says other major and you (probably) have datafiles!

 *
 * A (possible old) installation of OpenLDAP was detected,
 * installation will not proceed for now.
 *
 * As major version upgrades can corrupt your database,
 * you need to dump your database and re-create it afterwards.
 *
 *  1. /etc/init.d/slurpd stop ; /etc/init.d/slapd stop
 *  2. slapcat -l /root/ldapdump.1151611861.raw
 *  3. egrep -v '^entryCSN:' </root/ldapdump.1151611861.raw >/root/ldapdump.1151611861
 *  4. mv /var/lib/openldap-data/ /var/lib/openldap-data-backup/
 *  5. emerge --update \=net-nds/openldap-2.3.24-r1
 *  6. etc-update, and ensure that you apply the changes
 *  7. slapadd -l /root/ldapdump.1151611861
 *  8. chown ldap:ldap /var/lib/openldap-data/*
 *  9. /etc/init.d/slapd start
 * 10. check that your data is intact.
 * 11. set up the new replication system.
 *

!!! ERROR: net-nds/openldap-2.3.24-r1 failed.
Call stack:
  ebuild.sh, line 1555:   Called dyn_setup
  ebuild.sh, line 668:   Called pkg_setup
  openldap-2.3.24-r1.ebuild, line 160:   Called openldap_find_versiontags
  openldap-2.3.24-r1.ebuild, line 113:   Called openldap_upgrade_howto
  openldap-2.3.24-r1.ebuild, line 70:   Called die

!!! You need to upgrade your database first
!!! If you need support, post the topmost build error, and the call stack if relevant.