Python 3.6 (only) for 4.10? (was: Re: Samba 4.9rc1 and blocker bugs)

[Andrew Bartlett]

On Tue, 2018-07-03 at 23:03 +0300, Alexander Bokovoy wrote:
> On ke, 04 heinä 2018, Andrew Bartlett via samba-technical wrote:
> > On Tue, 2018-07-03 at 16:35 +0200, Andreas Schneider via samba-
> > technical wrote:
> > > Hello,
> > > 
> > > Samba 4.9rc1 will be released while I'm on vacation. I didn't find a release 
> > > bug for Samba 4.9 but there is a blocker which I opened:
> > > 
> > > Support building Samba with Python3
> > > https://bugzilla.samba.org/show_bug.cgi?id=13504
> > > 
> > > Alexander is working on it to get it ready in time and he just has a few 
> > > things failing. Thanks for your hard work on that Alexander. There is a 
> > > mailinglist threads which he updates with his progress.
> > 
> > I agree this is important, but we agreed as a team that we do not have
> > 'blocker bugs'.   (That is also why there is no release bug).
> 
> I think you are mixing up Python3 and waf upgrade. 

Then I suggest a bug re-title.  I asked the same on the bug. 

> We should have waf
> upgrade as a requirement for 4.9. Python3 is a next target.

OK, but we still don't do requirements, we only do regressions.  

Everybody's feature becomes a requirement otherwise.  This was a
deliberate policy change. 

> For waf upgrade I'm close to completing it:
> https://gitlab.com/samba-team/devel/samba/pipelines/25041255
> 
> This is still using Python 2 but waf 2.0.8 gets us possibility to run
> a build with Python 3.

OK.  But such a python3 build *must* then be forced to only complete if
--without-python (and so --without-ad-dc) is specified, as otherwise a
misleading impression of support and behaviour will be given.

> > I'm not hopeful that the many remaining issues around Samba's Python3
> > support can be addressed in the next few weeks.  Joe already found more
> > issues in Noel's recent patch set (but got dragged onto customer work),
> > and that is still just a WIP.  
> > 
> > Fundamental issues around LDB bytes and string handling and the
> > behaviour of str() in practice remain to be sorted out.
> > 
> > As I say on the bug, the best 4.9 can hope for is that the --without-
> > python build builds with python3. 
> > 
> > Finally, I think we do better to align for Samba 4.10.  Hopefully we
> > will have a RHEL8 by then, with Python 3.6+ on the system.  
> > 
> > While the build can naturally continue to operate with whatever waf
> > 2.0.8 is compatible with, I hope we can then set Python 3.6 as the
> > minimum Python version for runtime use.  (Backports of Samba using
> > Python will need to link to a backported Python3).
> > 
> > That in turn would allow us for 4.10, if we actually finish, to support
> > just one, modern Python at runtime (specifically in the AD DC also the
> > testsuite), which would help many, many things.
> 
> The goal is to get waf 2.0.8 for 4.9, otherwise we realistically
> would be set back for about a year in any python3 effort due to need to
> coordinate upgrades of waf code in libtdb/libldb/libtevent/libtalloc
> etc.

I'm sorry, I don't buy that.  We generally make a tdb/ldb/tevent/talloc
release before a major release anyway, and can do trivially.

Andrew Bartlett

-- 
Andrew Bartlett                       http://samba.org/~abartlet/
Authentication Developer, Samba Team  http://samba.org
Samba Developer, Catalyst IT          http://catalyst.net.nz/services/samba