ports/167368: Python version propagation breaks USE_PYTHON= usage for dependency builds

[Shane Ambler]

The following reply was made to PR ports/167368; it has been noted by GNATS.

From: Shane Ambler <FreeBSD at ShaneWare.Biz>
To: bug-followup at FreeBSD.org, mva at freebsd.org
Cc:  
Subject: Re: ports/167368: Python version propagation breaks USE_PYTHON= usage
 for dependency builds
Date: Sun, 29 Apr 2012 15:11:35 +0930

 While this pr originated from graphics/blender (ports/167061) I will fix
 that as it's own issue as I think the issue of python dependency
 versions should be kept separate.
 
 As for python versions I'm not sure if that can be improved or just
 needs to be a check for port maintainers to verify that leaf ports use
 compatible python versions to their dependants. Do we need to consider
 ports being installed against multiple python versions?
 
 For reference I missed this as I built openimageio with python bindings
 using USE_PYTHON=2.6+ which led to the openimageio pylib and
 boost-python-libs being installed in the py27 libdir. When the new
 blender port was then built (using py32) it saw openimageio was
 installed but done no check to verify that it was installed into the
 same/compatible version of python.
 
 This also propagated within tinderbox as I built openimageio first and
 the existing packages were installed for dependants without testing
 python versions used. For others testing with tinderbox, adding a step
 of removing python using dependant packages before building a new port
 could be useful. Maybe a new tinderbox command/option to search for
 python using dependant packages for a port to be removed.