Linux beijing 2.6.18-53.el5 #1 SMP Wed Oct 10 16:34:19 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux ./configure --prefix=/usr/rcf --disable-iconv --disable-debug make # One example shown, but all gcc commands have -g ... gcc -std=gnu99 -I. -I. -g -O2 -DHAVE_CONFIG_H -Wall -W -Wno-unused-parameter -c zlib/zutil.c -o zlib/zutil.o ...
The check for the C compiler got moved prior to the check for the --disable-debug option, and that made it ineffectual. I'm checking in a fix for this. Thanks for the report!