https://github.com/openargus/argus/pull/5

From dd987328bd2b99977a1a686a1a6b36d1a3155ff7 Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Fri, 25 Nov 2022 19:03:24 +0100
Subject: [PATCH] configure (AC_LBL_UNALIGNED_ACCESS): Avoid implicit function
 decls

Implicit function declarations were removed from the C language
in 1999.  Include the relevant header files to ensure that the
check still works with future compilers.  C99 also requires
to declare the return types of all functions.
--- a/acsite.m4
+++ b/acsite.m4
@@ -298,8 +298,10 @@ AC_DEFUN([AC_LBL_UNALIGNED_ACCESS],
 #      include <sys/types.h>
 #      include <sys/wait.h>
 #      include <stdio.h>
+#      include <stdlib.h>
+#      include <unistd.h>
       unsigned char a[[5]] = { 1, 2, 3, 4, 5 };
-      main() {
+      int main() {
       unsigned int i;
       pid_t pid;
       int status;
--- a/configure
+++ b/configure
@@ -5791,8 +5791,10 @@ else
 #      include <sys/types.h>
 #      include <sys/wait.h>
 #      include <stdio.h>
+#      include <stdlib.h>
+#      include <unistd.h>
       unsigned char a[5] = { 1, 2, 3, 4, 5 };
-      main() {
+      int main() {
       unsigned int i;
       pid_t pid;
       int status;