This bug is marked as fixed in 2.4.8, but I still see the same problem in the test suite in 2.4.10. Trying to start slapd with back-meta gives:
/home/devel/openldap/build-area/openldap2.3-2.4.10/debian/build/servers/slapd/.libs/lt-slapd: symbol lookup error: ../servers/slapd/back-meta/.libs/back_meta-2.4.so.2: undefined symbol: slap_idassert_parse_cf
Is this a regression since 2.4.8?
Looks more like an incomplete fix. The functions in question haven't changed since 2006. Since we're not using a hacked libltdl the problem you're seeing doesn't show up here. I guess you should have tested this sooner...
Additional patches for back-ldap/back-meta are now in HEAD; please test.