Not sure if this is a symptom of something else wrong underneath (doesn't appear to be);  when running "configure", I noted that the output when checking for zlib (if no --with or --without params were given to configure) there is no "yes" or "no" output and the check for "dbase" just runs off the same line, as per:

checking [...] zlib support... checking [...] dbase [...]

instead of something like:

checking [...] zlib support... no
checking [...] dbase library... no

Not being much of an autoconf user, I'm only guessing that it's because there's effectively no "else" component for the zlib check (like there is for the dbase check, for example).