Re: [gentoo-dev] Actions of python team, especially Arfrever wrt python eclass and python-3*

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

On Sun, Jun 06, 2010 at 01:03:48AM +0200, Thomas Sachau wrote:
> Am 05.06.2010 20:31, schrieb Harald van Dijk:
> > On Sat, Jun 05, 2010 at 05:49:08PM +0200, Thomas Sachau wrote:
> >> If any package does inherit python or distutils eclass, then those eclasses do pull in
> >> "dev-lang/python", which is unversioned, so it will always pull in the latest version, in this case
> >> python-3*. You could change this, so it allows any major installed slot to satisfy the python
> >> dependency.
> > 
> > A dependency on dev-lang/python *is* satisfied by any slot, any version. You've
> > been told so already, if I recall correctly.
> 
> Every slot and every version *should* satisfy a "dev-lang/python" dependency, but currently such
> unspecified version dependency does automaticly pull in the latest version/slot, which in case of
> python does mean python-3*, even when you have e.g. python:2.6 installed.

Fine, I'll be as explicit as possible: not quite. I have a Python 3-free system. I created
a dummy ebuild that does nothing but pull in unversioned python. Let's
see how it behaves.

$ emerge -pv python

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild  NS   ] dev-lang/python-3.1.2-r3 [2.6.5-r2] USE="gdbm ipv6 ncurses readline sqlite ssl threads tk (wide-unicode) xml -build -doc -examples -wininst" ELIBC="(-uclibc)" 9,558 kB

$ cat test-2.0.ebuild 
KEYWORDS="~amd64"
SLOT="0"
DEPEND="dev-lang/python"

$ emerge -pv test

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild  N    ] test/test-2.0  0 kB [1]

Total: 1 package (1 new), Size of downloads: 0 kB
Portage tree and overlays:
 [0] /usr/portage
 [1] /etc/portage/overlay

Note how python 3 is *not* pulled in, despite an unversioned dependency on dev-lang/python.
You only get that if you tell portage to try and update dependencies as
well, and yes, if you do that, it's only fair that it attempts to update python.