--- m4/needtrio.m4.orig	2016-02-20 07:57:52.000000000 -0600
+++ m4/needtrio.m4	2020-08-20 09:03:41.000000000 -0500
@@ -9,6 +9,7 @@
       else
 
       AC_RUN_IFELSE([AC_LANG_SOURCE([[
+     #include <stdio.h>
 	 int main()
 	 {
 	    unsigned long long x=0,x1;