Subject: Re: c-ares 1.5.3 build issues/resolutions

Re: c-ares 1.5.3 build issues/resolutions

From: Yang Tse <>
Date: Mon, 29 Sep 2008 04:48:16 +0200

2008/9/26, Brad House wrote:

> In
> It appears as though a manual check for AR is being performed
> which is infact causing issues if you want to use a different AR
> than exists in your path, it's always overwriting it without ever
> checking for the variable to have already been set.

Issues? Which ones?

With mostly any version of autoconf you _really_ need the tools to be
available in your path. Setting the AR variable before running
configure should work with all autoconf versions.

No matter what the autoconf manual says, AC_PATH_TOOL does read and
use the environment variable if properly set, at least from autoconf
2.57 up to 2.63. Remember to use an absolute path.

> I'm not sure
> why this check is being performed as it is one of the standard
> checks autoconf does already, and in a more sane manner, I'd
> suggest removing that block of code.

The check is done in order to allow early detection of misconfigured
or incomplete build toolchain and halt the configure process. This
allows the user to focus on the real error instead of getting hundreds
of warnings which would not really help him to fix the problem on his

Autoconf does not do this check at all, it is automagically pulled
from libtool which does the check, but this one does not halt the
configure process and after all the warnings the result is a failed
library build.

Could you elaborate on your affirmation "in a more sane manner" ?

> Then, similar checks are being done for GREP, EGREP, and SED,
> you should instead use the AC_PROG_GREP, AC_PROG_EGREP,
> and AC_PROG_SED macros as per:

Our configure script is compatible with autoconf 2.57, but
AC_PROG_SED and AC_PROG_GREP are not available until autoconf 2.60, so
this would require 2.60 for our configure script.

Received on 2008-09-29