Re: [gentoo-dev] perl eclass review - EAPI=3 + new helper eclass

["Harald van Dijk" <truedfx@gentoo.org>]

On Mon, Apr 19, 2010 at 04:58:57PM -0400, James Cloos wrote:
> >>>>> "CM" == Ciaran McCreesh <ciaran.mccreesh@googlemail.com> writes:
> 
> CM> There's no need to offer the user the choice to do something that is
> CM> always broken. Your car doesn't have a "connect the exhaust fumes to
> CM> the air conditioning intake" button.
> 
> Overriding portage's eclasses with one's own is not "always broken";
> your analogy is not at all on point.

Overriding portage's eclasses with your own is already possible. You're
asking to override portage's eclasses, without letting portage handle
the fact that you are overriding eclasses. And that is a bad idea. You
haven't commented, at least not in this thread that I have seen, on
how to handle metadata changes as a result of eclass changes.

Let's say this is in the tree:

foo.eclass:
DEPEND="dev-lang/python:2.6"

bar-1.ebuild:
inherit foo

Let's say this is in your overlay:

foo.eclass:
DEPEND="|| ( dev-lang/python:3.1 dev-lang/python:2.6 )"

Now you install bar. How should portage know that it must regenerate the
metadata cache, to see that it doesn't need to install python 2.6 if you
already have 3.1?