From 5005ade2ce57e0e71439aa6639eb70414db949b8 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Tue, 29 May 2018 10:26:06 +0200
Subject: [PATCH] configure: override AR_FLAGS to silence warning

The automake default ar flags are 'cru', but the 'u' flag in there
causes warnings on many modern Linux distros. Removing 'u' may have a
minor performance impact on older distros but should not cause harm.

Explained on the automake mailing list already back in April 2015:

https://www.mail-archive.com/automake-patches@gnu.org/msg07705.html

Reported-by: elephoenix on github
Fixes #2617
Closes #2619
---
 configure.ac | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 69a185044..f5f4e7717 100755
--- a/configure.ac
+++ b/configure.ac
@@ -188,7 +188,8 @@ AC_CANONICAL_HOST
 dnl Get system canonical name
 AC_DEFINE_UNQUOTED(OS, "${host}", [cpu-machine-OS])
 
-dnl Checks for programs.
+# Silence warning: ar: 'u' modifier ignored since 'D' is the default
+AC_SUBST(AR_FLAGS, [cr])
 
 dnl This defines _ALL_SOURCE for AIX
 CURL_CHECK_AIX_ALL_SOURCE