Fw: [PROPOSAL] To retire autoconf for 4.1

[Jelmer Vernooij]

On Fri, May 24, 2013 at 03:29:35PM +0200, Volker Lendecke wrote:
> On Fri, May 24, 2013 at 03:07:33PM +0200, Jelmer Vernooij wrote:
> > On Fri, May 24, 2013 at 08:30:10AM -0400, Simo wrote:
> > > On 05/24/2013 07:58 AM, yaberger at ca.ibm.com wrote:
> > > >http://wiki.python.org/moin/Python2orPython3
> > > >
> > > >I believe you're right, ie: when most major distributions will provide a
> > > >Python 3.x package in their repositories, Samba team should start working
> > > >on moving from Python 2.x to 3.x for Samba and Waf.
> > > >RHEL 6.4 is on 2.6.6
> > > >Debian 7 is on 2.7.3 but also have a package for Python 3.2.3
> > > 
> > > At SambaXP I and Alexander started raising a concern about this.
> > > Fedora is starting to plan to move to Python 3, so we need to start
> > > thinking about moving samba as well.
> > When will Fedora drop support for Python 2.x? Just having the default changed
> > shouldn't be a problem, so long as Python2.x is still installable.
> > 
> > > Unfortunately we cannot just make a full switch. Because there are
> > > distributions that will stay on Python 2.x for a long time, much
> > > longer than Fedora's support for Python 2.x presumably.
> > > 
> > > So we should really look into what it will take to try to support
> > > both 2.x and 3.x especially for generated bindings as the binding
> > > interface, I am told, changes quite some fundamental things.
> > > 
> > > A flag day where we switch fro 2 to 3 is highly unfeasible unless we
> > > also decide to drop support for all Enterprise Linux distributions
> > > and all other long term maintenance Unix flavors at the same time. I
> > > do not think that would be a wise choice.
> > I've tried to do support for both python2 and python3 with a few projects. It
> > requires ugly hacks that make the code less readable, is a major pain to keep
> > up and prone to regressions even for smaller projects. It would be
> > a nightmare for a project the size of Samba.
> This means that Python 3 is just a different language. If
> Fedora drops support for Python 2 it is almost the same as
> if they drop support for C/C++ given the enormous popularity
> of Python 2.
It is to some degree a different language. Python 3 is better in a lot of ways, but 
I'm not a fan of the way the transition from 2.x to 3.0 was managed - and it shows
in the number of packages that have migrated to 3.0. Unfortunately there's not
much we can do about that now.

Python2.7 makes life slightly simpler if you want to support 2.x and 3.x in the
same application by supporting a number of features that were introduced in
Python3. However, 2.7 was released around the same time as 3.0. So if we can
afford to drop support for Python < 2.7 we might as well switch to 3.0.

> If Fedora drops support for Python 2, why should we bother?
> If Fedora drops support for C, Samba would not switch to Ada
> or Haskell, right? We would just say that Fedora should
> really wake up and continue supporting us.

> Yes, I know this is vastly exagerrated, but if Fedora wants
> to drop supporting our infrastructure, it is up to them to
> provide patches to upstream, right?

> P.S: By the way, with configure/make we would not have this
> discussion, right?
If Fedora were to consider dropping Python2.x support while there was still
a large number of packages relying on it, I don't see why they wouldn't
consider to do the same with m4 or autoconf. Neither seems realistic.

I'm assuming Simo is participating in this discussion because Fedora cares
about migrating upstreams to Python3 before dropping Python2. 

Cheers,

Jelmer