how to enforce one version of python

[Ruslan Makhmatkhanov]

tech-lists wrote on 9/12/18 11:09 AM:
> Hello,
> 
> On 11/09/2018 15:54, Ruslan Makhmatkhanov wrote:
> 
>> No, it's because pylint2 as itself requires python > 3.4. User should 
>> switch to older devel/pylint1 if he needs to stick with 2.7.
>>
> 
> But I'm not upgrading pylint2:
> 
>  >>> (pylint-py27-1.9.2) wants to upgrade to pylint-py36-2.1.1

You upgrading to pylint mainline version (2.1), that was switched to 
python 3.x by upstream developers. Since version 2.0 pylint doesn't work 
with python 2. See: 
https://github.com/PyCQA/pylint/blob/master/doc/whatsnew/2.0.rst

If you need pylint version (1.9.3) that works (and depends upon) 
python2.7, you need to manually remove your current pylint package and 
install devel/pylint1 instead.

> Maybe I need to stop using portupgrade. What is the best replacement?

I see no reason to not use stock pkg :). If you absolutely need to make 
the packages with your customizations, it's better to build them with 
poudriere and then install/update with pkg.

> qt4 and qt5 has similar issues to python2 and python3. These are 
> installed as either build or runtime dependencies of other programs I 
> want to run. I just want a version to be picked and stuck with.
> 
> thanks,

It's essential process. qt4 is deprecated and no more supported, so 
application developers switching to the next supported qt branch, and so 
the corresponding changes landing in FreeBSD ports tree.

The same with python - python applications moving to python3 because 
python2 is deprecated and will not be supported after year 2020: 
https://pythonclock.org/

so developers tend to move forward to python3 and there is no issue with 
FreeBSD package repository - it simply adjusts to upstream requirements.

The only question I have there - why we still don't switched to python3 
by default?)

-- 
Regards,
Ruslan

T.O.S. Of Reality