This must be a trivial question. Consider the following test case debian_chroot:sid:kusumanchi:/home/625341/w2# cat test.c #include <sys/user.h> void test (long int a); void test (long int a) { a = NBPG; } debian_chroot:sid:kusumanchi:/home/625341/w2# gcc -c -Wall -Werror test.c test.c: In function âtestâ: test.c:7:5: error: implicit declaration of function â__sysconfâ [- Werror=implicit-function-declaration] cc1: all warnings being treated as errors What should I do to make this warning go away? I am trying to reduce the testcase for http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=627273 and fix the build failure. But no matter what I do, I am unable to eliminate the warning. I tried inserting #include <unistd.h> but that did not help. Any other suggestions? thanks raju -- Kamaraju S Kusumanchi http://malayamaarutham.blogspot.com/