[Boost-build] Building Boost with multiple python versions

Subject: [Boost-build] Building Boost with multiple python versions
From: Stefan Seefeld (stefan_at_[hidden])
Date: 2017-02-13 15:35:42

Hello,

having learned a bit more about Boost.Build and its internals, I'm
trying to apply my understanding.

My user-config.jam file contains

  using python : 2.7 ;
  using pyhon : 3.5 ;

Then I issue this command:

  ./b2 --with-python python=2.7

Inside my Jamfile, I see that `feature.values python` reports "2.7 3.5",
independently on what I specify on the command-line. So it seems I'm
missing something:

What is b2's interpretation of the above user-config.jam file ?
And what does it mean to provide the `python=2.7` option on the
command-line ?

How can I specify that I want to

* build with Python 2.7 only
* build with Python 3.5 only
* build both variants at the same time

Thanks,
        Stefan

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