>From 64d95effe459f7e7b02834a6ad1d7e5e092581a0 Mon Sep 17 00:00:00 2001 From: Pavel Raiskup Date: Wed, 1 Jul 2015 09:38:35 +0200 Subject: [PATCH 2/2] gnulib-common.m4: change the ARFLAGS default to 'cr' In some GNU/Linux distributions people started to compile 'ar' binary with --enable-deterministic-archives (binutils project). That, however, in combination with previous autotools long time working default AR{_,}FLAGS=cru causes warnings on such installations: ar: `u' modifier ignored since `D' is the default (see `U') The 'u' option (at least with GNU binutils) did small optimization during repeated builds because it instructed 'ar' to not open/close unchanged *.o files and to rather read their contents from old archive file. However, its removal should not cause a big performance hit for usual workflows. Distributions started using --enable-deterministic-archives knowing that it will disable the 'u', with the benefit of having rather a bit more deterministic builds. Also, to justify this change a bit more, keeping 'u' in ARFLAGS could only result in many per-project changes to override Automake's ARFLAGS default, just to silent such warnings. * m4/gnulib-common.m4 (gl_PROG_AR_RANLIB): Set ARFLAGS='cr' if not set already. --- m4/gnulib-common.m4 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4 index 613e8d5..34d0f20 100644 --- a/m4/gnulib-common.m4 +++ b/m4/gnulib-common.m4 @@ -296,7 +296,7 @@ Amsterdam dnl ${host}-ar over ar (useful for cross-compiling). AC_CHECK_TOOL([AR], [ar], [ar]) if test -z "$ARFLAGS"; then - ARFLAGS='cru' + ARFLAGS='cr' fi AC_SUBST([AR]) -- 2.1.0