Re: [Boost-build] Boost.Build loading wrong build system?

From: Vladimir Prus (ghost_at_[hidden])
Date: 2007-08-03 08:14:42

On Saturday 21 July 2007 20:38:22 Roland Schwarz wrote:
> 
> Vladimir Prus wrote:
> > ... I'd only have to
> > dig CVS history to understand why the 'boost-build' rule
> > works the way it works now -- appending the argument rather than
> > prepending it.
> 
> This is what I found:
> 
> ===
> Fix order of directories in BOOST_BUILD_PATH.
> 
> In 'boost-build', add the directory given as argument *after* existing
> directories. So, if user set in environment
> BOOST_BUILD_PATH=/home/custom_bb_files, then files from that directory
> will be loaded before any stock files.
> 
> In particular, this fixes searching of user-config.jam in environmental
> BOOST_BUILD_PATH.
> ===
> 
> To be honest, I have no idea what "stock files" is.
> But perhaps you remember?

Ok,
so there's what was the deal: Martin wanted to be able to
have several user-config.jam files, and point bjam at the one
he wants with BOOST_BUILD_PATH. One way to implement that
is the search for everything first in BOOST_BUILD_PATH
and then in whatever is passed to the 'boost-build' rule.
Unfortunately, Jambase initializes sets BOOST_BUILD_PATH to
/usr/share/boost-build on Linux, so if /usr/share/boost-build
exists, then argument to boost-build is ignored.

The first fix is probably to look in /usr/share/boost-build
after other locations.

However, I'm not sure if environmental BOOST_BUILD_PATH
or the path given to 'boost-build' should be searched first.
A project having its own copy of Boost.Build
will probably want that copy to be always used, no matter
what -- because that copy is known to work -- so
BOOST_BUILD_PATH should be searched after argument to
boost-build. But if we make this change, it won't be
possible to override user-config.jam via BOOST_BUILD_PATH.

Martin, do you think it will be OK for you to use 

        --user-config=/some/path/user-config.jam

when invoking bjam, as opposed to setting BOOST_BUILD_PATH?

- Volodya