RHEL6 blocking Python 2.7 and 3.x

[Andrew Bartlett]

On Wed, 2015-09-02 at 18:24 -0400, Simo wrote:
> On Thu, 2015-09-03 at 09:37 +1200, Andrew Bartlett wrote:
> > On Wed, 2015-09-02 at 09:50 +0200, Lukas Slebodnik wrote:
> > > On (02/09/15 09:56), Andrew Bartlett wrote:
> > > > On Tue, 2015-09-01 at 20:04 +0200, Matthias Dieter Wallnöfer
> > > > wrote:
> > > > > Hi Andrew,
> > > > > 
> > > > > it is CentOS 5 which uses this older GNUTLS release (1.4.1).
> > > > > 
> > > > > Well I do not complain if we are not supporting it any longer
> > > > > but > > > 
> > > > > then
> > > > > we should change our WAF checks to exclude it.
> > > > > 
> > > > > Matthias
> > > > 
> > > > Can you prepare such a patch.  If accepted this may also give
> > > > us 
> > > > the
> > > > excuse to move to Python 2.7 as a minimum as well (presuming
> > > > that
> > > > doesn't cause other problems).
> > > > 
> > > CentOS 6 has just Python 2.6
> > > So some users might complain they are not able to build samba on 
> > > CentOS 6.
> > 
> > This will indeed be a major impediment to our move to Python3.  
> > 
> > Ouch.
> > 
> > Andrew Bartlett
> 
> This was clear and obvious.
> Samba has no option but to support both python2 and python3 for a t
> lest a few years. You can't just make a clean cut and switch, it
> simply
> is not going to work for at least half of the users.
> 
> distributions also need to be able to provide modules for both
> python2
> and python3 at the same time, or it will be really hard to make any
> transition with the wide set of interlocked dependencies.

What was implicit, but not stated in my frustration here is that I've
been told that in general, making python code compatible with Python3
first requires that Python 2.7 be the minimum version.  Thankfully the
current proposals to fix up the C API don't require this, but the
effort will need to turn to the Python Python soon.

I've always assumed (and argued) that our users would only accept Samba
depending on software in base RHEL or at most EPEL, but to test the
counter-point: Are software collections[1] suitable for Samba to depend
on for Python[2] purposes?

Note that we already depend on EPEL for Python on RHEL 5 (as the system
python is very, very old), and there were no complaints. 

Thanks,

Andrew Bartlett

[1] https://www.softwarecollections.org/en/
[2] https://www.softwarecollections.org/en/scls/rhscl/python27/
-- 
Andrew Bartlett                       http://samba.org/~abartlet/
Authentication Developer, Samba Team  http://samba.org
Samba Developer, Catalyst IT          http://catalyst.net.nz/services/samba