Re: [gentoo-project] For next council meeting: moving Portage to python3.6+

[R0b0t1]

On Sat, Feb 24, 2018 at 2:57 AM, Michał Górny <mgorny@g.o> wrote:
> W dniu pią, 23.02.2018 o godzinie 19∶58 -0700, użytkownik Daniel Robbins
> napisał:
>> Hi there,
>>
>> Zac Medico and I would like to discuss the following at the next council
>> meeting: moving Portage to support only python3.6+. One of the primary
>> benefits of this change is that it will allow us to use python's native
>> async implementation as we look to make Portage faster at a critical time
>> when we are looking to improve Portage performance. As we approach the
>> stabilization of python3.6 in Gentoo, it seems like a good time to discuss
>> the process of jettisoning 2.7 support and standardizing on 3.6 for Portage.
>>
>> Right now, a custom 'asyncio-like' set of classes is used for async in
>> Portage. This limits interoperability with other async-friendly python
>> modules and produces additional maintenance overhead for the project.
>>
>> Maybe even more importantly, 3.6+ compatibility also gives us the ability
>> to use many other new language features and reduce the maintenance overhead
>> of having 2.7 compatibility for the extensive Portage code-base. We expect
>> that this will improve the velocity of Portage development, provide
>> opportunities to improve Portage functionality and also allow us clean up a
>> lot of unnecessarily complex code (and eliminate code) that is there only
>> to ensure compatibility with 2.7.
>>
>
> This is Portage's team decision. The Council has already voted on for
> how long upgrade path needs to provided (that was 2 years, I think)
> and what Portage developers decide beyond that is up to them.
>
> I personally don't have anything against removing support for Python 2
> (though I think many users would do). However, I wouldn't go up to 3.6+
> at once, especially if 3.5 is the current version we are using. Even if
> we switch the default, I think it'd be reasonable to provide a lengthy
> grace period not to make upgrading Portage PITA.
>

I am a stain upon this mailing list and my opinion is of no
consequence, but I think moving directly to 3.6 would be the best
option. Python 3.5 is a very strange situation and has some half
finished features despite being a full release. It is very likely the
release of 3.6 was rushed to fix some of what was "wrong" in 3.5
(mainly missing async features, but there are many).[1] These new
features are useful enough that they will likely outweigh any
additional work involved in adopting 3.6.

Python 2.7 will still be necessary for some hardened utilities, from memory.

Cheers,
     R0b0t1


[1]: https://docs.python.org/3/whatsnew/3.6.html