make: don't know how to make libgzip.. Stop

Solution found at
http://www.tequilafish.com/2005/11/04/apache-mod_gzip-no-rule-to-make-target-libgzip/

It turns out that there’s an entry in mod_gzip’s Makefile.tmpl file that confuses my system. The very first line of src/modules/gzip/Makefile.tmpl uses a variable named LIBEXT that’s not defined on my system, so it fails. It’s an easy fix, open up src/modules/gzip/Makefile.tmpl for editing and find:

LIB=libgzip.$(LIBEXT)

And replace with:

LIB=libgzip.a

Save & Exit, run make clean; make; make install in the Apache src dir and you should be good to go