From f3609abde3f2585497cfd22b4b89416b39727f9d Mon Sep 17 00:00:00 2001
From: Vincent Bernat <vincent@bernat.ch>
Date: Tue, 21 Sep 2021 09:52:15 +0200
Subject: [PATCH] build: fallback to use autoconf 2.69 again

Unfortunately, Ubuntu, used for CI on GitHub does not have 2.70 which
is needed for `AC_PROG_CC` to test for C99.
---
 configure.ac | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index c855234c..995b01d2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5,7 +5,7 @@
 ### Base configuration
 
 # Configure autoconf
-AC_PREREQ([2.71])
+AC_PREREQ([2.69])
 
 AC_INIT([lldpd],
         [m4_esyscmd_s([./get-version])],
@@ -44,6 +44,7 @@ gl_LD_VERSION_SCRIPT
 
 # Checks for programs.
 AC_PROG_CC
+AC_PROG_CC_C99
 if test x"$ac_cv_prog_cc_c99" = x"no"; then
   AC_MSG_FAILURE([*** C99 support is mandatory])
 fi
-- 
2.39.5