[gentoo-python] Python 3 in Gentoo

[Mike Gilbert]

This past weekend, the topic of the current state of Python 3 in Gentoo
was raised once again in the #gentoo-dev IRC channel. Here's where we
currently stand:

1. Python 3.2 is installed by default on major arches due to its
presence in the stage3 tarball.

2. Python 2 is NOT installed by default as nothing in the system set
actually depends on it.

3. In most cases, users end up building and installing Python 2.7 as a
dependency of some other package once they have their system set up.
Users end up having two versions of Python installed.

This third point is the cause of some annoyance for several (many?)
developers and users. In most cases, there really is no reason for a
user to have two versions of Python installed; it is simply a redundant
set of code. However, if you attempt to remove Python 3, portage will
just pull it back on the next world upgrade unless you mask it.

I don't think this makes for a very good user experience. So, how can we
change that?

As I see it, we need a way to avoid portage's overly optimistic upgrade
mechanic. One way to do that is to drop the stable keywords on Python 3,
but I feel that is dishonest; Python 3 itself is perfectly stable, so we
should not force users to unmask it.

The other way that occurs to me (and others) is to rename
dev-lang/python-3* to dev-lang/python3, treating it as an entirely
separate package. I believe this has been proposed in the past, and I'm
honestly not sure why it never gained traction. It would take some work,
but we have already had a couple of non-python devs volunteer to help out.

We can work out the technical details in follow-up discussion.

Is anyone in favor or opposed to this package rename idea? Are there any
better ideas?