Personally, I think have -I., -I.., etc. is really bad. This causes #include "config.h" and #include <config.h> to be equivalent. However, there could be both a local config.h and a config.h somewhere in the system include directory. I would be better if slapd/config.h was included here by: #include "../config.h" and -I.. not be added to the include path. It possible -I.. is causing a system header to be eclipsed by the local header. Namely, /opt/local/lib/perl5/5.8.8/darwin-2level/CORE/config.h.