Include config.h so it can define const away for K&R.
diff --git a/Modules/getbuildinfo.c b/Modules/getbuildinfo.c
index 0bf031a..66ba1c4 100644
--- a/Modules/getbuildinfo.c
+++ b/Modules/getbuildinfo.c
@@ -1,3 +1,5 @@
+#include "config.h"
+
 #include <stdio.h>
 
 #ifndef DATE