The constant SYS_NMLN is only available ifdef _SVID_SOURCE in glibc. Signed-off-by: Erik van Konijnenburg <ekonijn@xs4all.nl> Index: exec/ipconfig/main.c ==================================================================--- exec.orig/ipconfig/main.c 2005-05-21 13:18:45.000000000 +0200 +++ exec/ipconfig/main.c 2005-05-21 13:47:08.000000000 +0200 @@ -2,6 +2,7 @@ * ipconfig/main.c */ #define _XOPEN_SOURCE /* for POLLRDNORM */ +#define _SVID_SOURCE /* for SYS_NMLN */ #include <errno.h> #include <poll.h> #include <limits.h> --