-fno-common

Index: src/dep.h
--- src/dep.h.orig
+++ src/dep.h
@@ -139,7 +139,7 @@ struct dep *copy_dep_chain (const struct dep *d);
 struct goaldep *read_all_makefiles (const char **makefiles);
 
 /*! The chain of makefiles read by read_makefile.  */
-struct goaldep *read_makefiles;
+extern struct goaldep *read_makefiles;
 
 void eval_buffer (char *buffer, const gmk_floc *floc);
 enum update_status update_goal_chain (struct goaldep *goals);
