diff -rup a/configure b/configure
--- a/configure	2023-03-02 17:44:12.665200667 -0500
+++ b/configure	2023-03-02 18:03:13.749177341 -0500
@@ -11996,7 +11996,8 @@ _ACEOF
 cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
-
+#include <string.h>
+#include <stdio.h>
 int
 main ()
 {
diff -rup a/m4/ggz/c99.m4 b/m4/ggz/c99.m4
--- a/m4/ggz/c99.m4	2009-01-02 14:32:32.000000000 -0500
+++ b/m4/ggz/c99.m4	2023-03-02 18:02:20.951201168 -0500
@@ -46,7 +46,8 @@ AC_DEFUN([AC_C99_VARIABLE_ARRAYS],
   AC_CACHE_CHECK([for C99 variable arrays],
     [ac_cv_c99_variable_arrays],
     [AC_TRY_COMPILE(
-        [],
+        [#include <string.h>
+#include <stdio.h>],
         [char *s1 = "foo", *s2 = "bar";
          char s3[strlen(s1) + strlen(s2) + 1];
          sprintf(s3, "%s%s", s1, s2);],