Fixed now in HEAD. For reference, here is the original config LDIF I slapadd'd:
#### dn: cn=config objectClass: olcGlobal cn: config
dn: cn=module{0},cn=config objectClass: olcModuleList cn: module{0} olcModuleLoad: ../servers/slapd/back-monitor/back_monitor.la olcModuleLoad: ../servers/slapd/back-hdb/back_hdb.la
dn: cn=schema,cn=config objectClass: olcSchemaConfig cn: schema
include: file:./schema/core.ldif
include: file:./schema/cosine.ldif
include: file:./schema/inetorgperson.ldif
dn: olcDatabase=config,cn=config objectClass: olcDatabaseConfig olcDatabase: config olcRootPW: secret
dn: olcDatabase=monitor,cn=config objectClass: olcDatabaseConfig olcDatabase: monitor
dn: olcDatabase=hdb,cn=config objectClass: olcDatabaseConfig objectClass: olcHdbConfig olcDatabase: hdb olcSuffix: olcRootDN: cn=Manager olcRootPW: secret olcDbDirectory: ./testrun/db.1.a olcDbIndex: objectClass eq olcDbIndex: cn pres,eq,sub olcDbIndex: uid pres,eq,sub olcDbIndex: sn pres,eq,sub
####
Followed by ldapmodify with this LDIF:
#### dn: cn=module{0},cn=config changetype: modify add: olcModuleLoad olcModuleLoad: ../servers/slapd/overlays/syncprov.la olcModuleLoad: ../servers/slapd/overlays/accesslog.la
dn: olcDatabase={2}hdb,cn=config changetype: add objectClass: olcDatabaseConfig objectClass: olcHdbConfig olcDatabase: {2}hdb olcDbDirectory: ./testrun/db.2.a olcSuffix: cn=accesslog olcAccess: {0}to dn.subtree="cn=accesslog" by dn.exact="uid=zimbra,cn=admins,cn=zimbra" read by dn.exact="cn=config" read by dn.exact="uid=zmreplica,cn=admins,cn=zimbra" read olcRootDN: cn=config olcDbCacheSize: 10000 olcDbCheckpoint: 64 5 olcDbIDLcacheSize: 10000 olcDbIndex: entryCSN eq olcDbIndex: objectClass eq olcDbIndex: reqEnd eq olcDbIndex: reqResult eq olcDbIndex: reqStart eq olcDbMode: 0600 olcDbCacheFree: 1 olcDbDNcacheSize: 20000
dn: olcOverlay=syncprov,olcDatabase={2}hdb,cn=config changetype: add objectClass: olcOverlayConfig objectClass: olcSyncProvConfig olcOverlay: syncprov olcSpNoPresent: TRUE olcSpReloadHint: TRUE
dn: olcOverlay=syncprov,olcDatabase={3}hdb,cn=config changetype: add objectClass: olcOverlayConfig objectClass: olcSyncProvConfig olcOverlay: syncprov olcSpCheckpoint: 20 10 olcSpSessionlog: 500
dn: olcOverlay=accesslog,olcDatabase={3}hdb,cn=config changetype: add objectClass: olcOverlayConfig objectClass: olcAccessLogConfig olcOverlay: accesslog olcAccessLogDB: cn=accesslog olcAccessLogOps: writes olcAccessLogSuccess: TRUE olcAccessLogPurge: 07+00:00 01+00:00
####