[Boost-build] Finding boost-build.jam upon invocation of bjam

Subject: [Boost-build] Finding boost-build.jam upon invocation of bjam
From: Edward Diener (eldiener_at_[hidden])
Date: 2010-12-01 20:03:52

I think it would be very useful if the sequence of finding 
boost-build.jam upon invocation of 'bjam' took into consideration the 
--boost option passed to 'bjam' and looked in that directory also for a 
boost-build.jam file as a last resort.

The reason I am suggesting this is because a possible Boost library 
distributed in the suggested directory structure for sandbox libraries 
would not need to have its local directory beneath a filesystem tree 
which had a boost-build.jam for 'bjam' to work as long as a 
'--boost=path/to/boost/distribution' were specified on the 'bjam' 
command line in order to point to a Boost distribution. Whereas 
currently, if a possible Boost library is not placed locally beneath a 
directory with its boost-build.jam, such as occurs when one checks out 
the top-level sandbox directory files, its jam files will not work at 
all even if the end-user invoking them uses the 
'--boost=path/to/boost/distribution' option.

I believe any Boost-like library, no matter where the end-user places it 
on his local system, should have their jam files working correctly as 
long as the '--boost=path/to/boost/distribution' option is used to point 
to a Boost distribution or the library itself is copied/moved into a 
Boost distribution structure.

I do understand that one can set the environment variable to 
BOOST_BUILD_PATH to point to boost build. But I think that requiring an 
environment variable to be set rather than allowing for the flexibility 
of the '--boost=path/to/boost/distribution' to find boost build in the 
top-level directory of an installation is a much poorer alternate way of 
working.