File mpich-fix_headers.diff of Package mpich

Index: mpich-1.2.7p1/mpid/server/serv_p4.c
===================================================================
--- mpich-1.2.7p1.orig/mpid/server/serv_p4.c	2010-01-22 12:06:37.000000000 +0100
+++ mpich-1.2.7p1/mpid/server/serv_p4.c	2010-01-22 12:24:04.000000000 +0100
@@ -41,6 +41,7 @@
 #endif
 
 #ifdef HAVE_UNISTD_H
+#define __USE_GNU
 #include <unistd.h>
 #endif