Parallel Python packages for different versions w/ pkgng

[Mark Felder]

On Wed, Nov 6, 2013, at 19:17, KT Dassoff wrote:
> Hey all,
> I had a question about installing multiple copies of Python packages
> from ports for different versions of Python (e.g. installing Sphinx for
> both Python 2.7 and Python 3.3). Now, I know to set the PYTHON_VERSION
> environment variable when building the appropriate py-* port. And the
> generated package will have the expected prefix (i.e. py27-* or py33-*
> etc).
> 
> The problem is that ports/pkgng will treat a py27-* package and a py33-*
> package as different versions to be upgraded even though, as far as I
> know, they install their files to different site-packages trees
> according to the interpreter they're built for, and if I recall, this
> worked fine with the older package infrastructure.
> 
> Example:
> * Install `textproc/py-sphinx` with no PYTHON_VERSION set (equivalent to
> =2.7); that succeeds, and `pkg info` later shows py27-sphinx installed
> * Install the same port with PYTHON_VERSION set to 3.3; the port will
> build fine, but when running `make install` (whether directly or via
> portmaster), it will try to replace py27-sphinx with py33-sphinx by
> deinstalling py27-sphinx before installing the py33 version
> 
> Is there something else I need to do to install them side-by-side, or is
> this some bug in pkgng, or is there some actual conflict between Python
> packages via ports that I'm not aware of?
> 

The pkg and ports team is working on fixing package name conflicts in
the ports tree. Right now packages are identified by their origin in the
ports tree. Both py27-sphinx and py33-sphinx have the same origin,
textproc/py-sphinx, so they conflict. This will be resolved soon^TM when
they're able to flip the switch to working with package names. I'm
pretty sure your scenario will work just fine then.