Python does not conform to this. It only supports one
version of python 2 and one version of python 3 which
are determined solely by the configuration files and
cannot be overridden on the command line.
That's exactly what I'd like to fix. In fact, there are multiple issues
I'd like to fix, but to do that I need to understand what behaviour
would be consistent with the rest of b2.
Here are the issues I want to address:
* `b2 python=<N>` doesn't have any effect, when it really should pick a
single python version
* the current logic builds at most two versions, as you say: at most one
python 2 and one python 3 version. For consistency we should build as
many versions as are selected
* a requirement for the last point: instead of just appending '3' to the
library name iff it's built with Python 3, the real Python version, i.e.
<major><minor> (without the dot) should be appended.