-fno-common

Index: src/variable.c
--- src/variable.c.orig
+++ src/variable.c
@@ -29,6 +29,7 @@ this program.  If not, see <http://www.gnu.org/license
 #endif
 #include "hash.h"
 #include "main.h"
+#include "globals.h"
 
 /* Incremented every time we add or remove a global variable.  */
 static unsigned long variable_changenum;