[OE-core] moving OpenEmbedded-core to Python 3

[Alexander Kanavin]

On 04/25/2016 06:11 PM, akuster808 wrote:
>> we want to deprecate Python 2 in oe-core and set Python 3 as the
>> default, preferred choice. What does this mean?
>
> What is the target to make  Python3 default, 2.2?

There is no specific target when the task is 'totally done', it's an 
ongoing activity that will span multiple releases. I plan to have the 
initial patchset merged into master in 2.2 cycle, but there's more work 
to be done when upstream components currently stuck in python 2 will 
finally more to python 3, and fixing up any loose ends, obscure 
regressions etc.

>> 1) Introducing new Python 2 dependencies via new recipes or additional
>> DEPENDS etc. in existing recipes will be discouraged: you'll have to
>> provide a reason.
>
> Will there be any kind of QA warning for these dependencies? this will
> help  scope how many recipes need to be looked at. there are a lot of
> layers out there.

I think there will not be. There are too many recipes in oe-core that 
are python 2 only (and even more outside of oe-core), and it's too much 
work to add warning suppressions to them all. Also, we don't want to 
force python 3 transition on anyone outside of oe-core, people can do it 
at their own pace and schedule.

>> 2) Bitbake itself is at the moment Python 2 only - which will be addressed.
>
> What will the env setup script display then?

This is a question for bitbake developers I guess, not me.

Alex