Re: [Boost-build] Using Environment Variables in Boost.Build JamRoot file

From: Juergen Hunold (juergen.hunold_at_[hidden])
Date: 2007-05-29 15:02:19

Hi Lawrence !

On Dienstag 29 Mai 2007, Lawrence Spector wrote:
> I'm having an issue where I can't use the Windows Environment
> variables in the JamRoot file.  
> When, in reality, my preference would be this:

> # Specify the path to the Boost project.  If you move this project,
> # adjust the path to refer to the Boost root directory.
> use-project boost
>   : $(BOOST_ROOT);
>
> However, when I take the second approach, I get the following errors:

That's because environment variables are not import by default. You have 
to explicitly do it. Just put

import os ;
local BOOST_ROOT  = [ os.environ BOOST_ROOT ] ;
use-project /boost : $(BOOST_ROOT) ;

into your Jamroot. Or put it in user-config.jam or site-config.jam for 
all projects :-))

This is explained in the manual at

http://boost.org/boost-build2/doc/html/bbv2/faq/envar.html

> My boost-build.jam seems to take the environment variable with no
> issue.

Yes, boost-build.jam behaves differently. It evaluates the environment 
to set up the build system. Slightly different magic ;-)) Look at the 
docs for the details, please.

> Thanks in advance,

You're welcome.

Hope this helps,

Yours,

Jürgen

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