[Boost-build] [bbv1]A question about Boost.Build v1

From: Zhuhui Chen (ekschencn_at_[hidden])
Date: 2007-01-02 21:25:27

I just want to apply Boost.Build v1 to my small project for practice.
Something I couldn't understand happened.

A simplified hierarchy of my project looks like:
prj-root
+---sources
+-------sources.c
+---headers
+-------sources.h

A main target was written like this :
subproject sources ;
lib foo
: sources.c
: <include>../headers
: release
;
and the Jamfile was located in "sources"

I invoked bjam -n and got the corresponding gcc command-line it actually
invoked, with an include path :
-I"../headers"
That was what I have desired. But when I went back to "prj-root" and
invoked bjam -n again, it gave me a different one :
-I"sources/headers"
Of course I have placed a Jamfile in "prj-root" with a subinclude
statment. Surely the compile-action failed.

Can anyone explain why the Boost.Build v1 System translate the include
path in the requirement in such a manner?