Do not build with zlib.

specbuilder/specbuilder/darwin.py

@@ -53,6 +53,9 @@ def load():
         'optflags':                '-O2 -fasynchronous-unwind-tables',
         '_smp_mflags':             smp_mflags,
         '__xz':                    '/usr/local/bin/xz',
+        # Work around the broken sed code on BSD sed
+        #'without_gcc_std':         'True',
+        'with_zlib':               '--with-zlib=no',
         }
     return defines