Re: [gentoo-python] python-distutils.eclass vs. python.eclass + distutils.eclass

[Nikolaj Sjujskij]

Den 2012-05-26 17:33:45 skrev Mike Gilbert <floppym@g.o>:

>>  Let's take a "stable" user who updates (`emerge --update --deep
>> --newuse
>> @world`) his/her system regularly.
>> Python 3.3 is released, added to Portage tree and eventually unmasked.
>> PYTHON_TARGETS variable is changed to include 3.3. And suddenly `emerge
>> --newuse @world` on stable system suggests rebuilding of every package
>> using
>> new eclass, because new (though disabled) USE-flags was added. And when
>> Python 3.3 is keyworded stable, hence bringing new default
>> PYTHON_TARGETS,
>> user should now rebuild those packages once more, but now, at least, not
>> uselessly.
> This is why I do my world updates with --changed-use instead of
> --newuse. The package manager already has the ability to deal with
> such scenarios intelligently, you just have to let it.
  Point taken, but --newuse is still "recommended" option (i.e.,  
`--depclean` suggests it and Handbook describes it as well). Whereas  
'--changed-use' is more or less "spoken lore" among users.

> I did not speak up in the previous thread, but here are some of the
> advantages to a use flag based approach (PYTHON_TARGETS):
> ...
  Agreed.

> Here is how I justify the current default value of PYTHON_TARGETS: Due
> to past decisions, python3.2 is installed by default on all amd64 and
> x86 systems, so having python3_2 enabled by default makes sense.
> However, there are many things do not work in python 3, so the
> python2_7 target is a necessity.
  Yes, I understand that. It is really the most sensible default in the  
circumstances.
Still, it is a bit clumsy with new installs. It'd be nice if stage3 had  
PYTHON_TARGETS="python32" (since it's the only Python interpreter  
installed), while profile had current default.
Of course, news item is a must for that kind of thing. Describing new  
variable, suggesting `--changed-use` instead of `--newuse` etc.