Re: [Boost-build] Pointing to a Boost tree for bjam

Subject: Re: [Boost-build] Pointing to a Boost tree for bjam
From: Vladimir Prus (ghost_at_[hidden])
Date: 2010-11-16 10:50:05

On Tuesday, November 16, 2010 18:24:22 Edward Diener wrote:

> Sure <g> ! Here are some irritating questions, honestly asked.
> 
> Where is the BOOST environment variable documented and what does it
> point to ?

I am not aware of such environment variable.

> 
> Where is the BOOST_ROOT environment variable documented and what does it
> point to ?

I am not aware of such environment variable either. Any Jamfile inside the 
official boost tree can use the BOOST_ROOT variable (which is Jam variable,
not environment variable), which is defined in Jamroot via path-constant,
as the path of Jamroot's directory.

> There is also a BOOST_BUILD_PATH environment variable mentioned in the
> Boost Build documentation but there is no  mention there what it means,
> although I gather from another comment that it points to the Boost Build
> v2 subdirectory of some Boost tree.

The value of BOOST_BUILD_PATH *environment variable* specifies where
to find *.jam files. Unless you have written your custom .jam files, you
should not need to set it to anything.

> Shouldn't there be some central place in the Boost documentation where
> all the environment variables used by BOOST, which may or may not need
> to be set, are actually documented for easy understanding.

There should be such a page, though none of environment variable you
have listed above actually need to be ever set when building official
Boost. 

I would agree that the official approach for making sandbox libraries
find Boost is desired -- did you look at Daniel's example?

- Volodya

-- 
Vladimir Prus
http://vladimir_prus.blogspot.com
Boost.Build: http://boost.org/boost-build2