[Boost-build] Using extension modules

Subject: [Boost-build] Using extension modules
From: Stefan Seefeld (stefan_at_[hidden])
Date: 2018-10-29 14:46:57

Hi,

I just merged some GSoC work into Boost.uBLAS. This contains two 
Boost.Build "extension modules" ("opencl.jam" and "clblas.jam"), which 
are used in Jamfiles ("using clblas ;", for example in 
https://github.com/boostorg/ublas/blob/develop/test/opencl/Jamfile).

What is the proper way to

* point `b2` to  find these modules ? (I can of course set 
BOOST_BUILD_PATH, but I find that not very scalable. Should I ask all 
Boost users & testers to do that ? Isn't there a way to set this 
programmatically, from within the project's Jamfile ?)

* add a way to deal with the case where the modules aren't found. Right 
now `./b2` will abort with an error. I'd prefer to print a warning and 
then skip the parts that require it.

Thanks,

Stefan

--
       ...ich hab' noch einen Koffer in Berlin...