I'm trying to compile mod_ruby as per the instructions on http://www.howtoforge.com/perfect-server-centos-5.3-i386-ispconfig-2-p6 After adding this to fix a previous error: Code: #ifndef APACHELIB_H #define APACHELIB_H #define OPT_INCNOEXEC 32 #endif I get this new error: Code: # make gcc -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i386 -mtune=generic -fasynchronous-unwind-tables -Wall -fno-strict-aliasing -fPIC -Wall -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i386 -mtune=generic -fasynchronous-unwind-tables -fno-strict-aliasing -DLINUX=2 -D_REENTRANT -D_GNU_SOURCE -D_LARGEFILE64_SOURCE -pthread -I. -I/usr/lib/ruby/1.8/i386-linux -I/usr/lib/ruby/1.8/i386-linux/i386-linux -I/usr/include/httpd -I/usr/include/apr-1 -c apachelib.c apachelib.c: In function âap_chdir_fileâ: apachelib.c:149: warning: ignoring return value of âchdirâ, declared with attribute warn_unused_result apachelib.c:154: warning: ignoring return value of âchdirâ, declared with attribute warn_unused_result apachelib.c: In function ârb_init_apacheâ: apachelib.c:374: error: âOPT_INCNOEXECâ undeclared (first use in this function) apachelib.c:374: error: (Each undeclared identifier is reported only once apachelib.c:374: error: for each function it appears in.) make: *** [apachelib.o] Error 1 # Any helpful suggestions?