[Boost-build] How to specify "ar" path?

Subject: [Boost-build] How to specify "ar" path?
From: Steve Soule (sts11dbxr_at_[hidden])
Date: 2010-04-23 20:28:37

On my Suse Linux 11.2 x86_64 machine, I have the MinGW Windows
cross-compiler installed (from the OpenSuse Build Service).  The
executables for g++ and ar are:

/usr/bin/i686-pc-mingw32-g++
/usr/bin/i686-pc-mingw32-ar

If I specify the following in my user-config.jam file:

using gcc : mingw : /usr/bin/i686-pc-mingw32-g++ ;

then Boost Build can find the right g++ executable, but not the right ar
executable.  It tries:

/usr/bin/ar

which doesn't work because /usr/bin/ar doesn't understand non-Linux
object files.

To work around this problem, I created a directory /home/soule/mingw
with symlinks to the mingw g++ and ar, and used the following
user-config.jam instead:

using gcc : mingw : /home/soule/mingw/g++ ;

This works fine, but is a kludge.  There must be some way to specify the
path to ar in the "using gcc" rule.  But I haven't found it in the
documentation.

How do I specify the path to ar?