Once you have run the configure script the last line of output should be:
Please "make depend" to build dependencies
If the last line of output does not match, configure has failed, and you will need to review its output to determine what went wrong. You should not proceed until configure completes successfully.
To build dependencies, run:
make depend
Now build the software, this step will actually compile OpenLDAP.
make
You should examine the output of this command carefully to make sure everything is built correctly. Note that this command builds the LDAP libraries and associated clients as well as slapd(8).