diff -ur a/build/dbm.m4 b/build/dbm.m4
--- a/build/dbm.m4	2013-11-23 13:00:53.000000000 -0500
+++ b/build/dbm.m4	2023-10-22 20:16:37.764571446 -0400
@@ -235,7 +235,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <$apu_try_berkeley_db_header>
-main ()
+int main ()
 {
   int major, minor, patch;