[arch-dev-public] [RFC] Python 3.3.0 and PEP 394

[Allan McRae]

On 13/09/12 20:32, Ray Rashif wrote:
> On 13 September 2012 12:18, Allan McRae <allan at archlinux.org> wrote:
>> On 13/09/12 10:00, Stéphane Gaudreault wrote:
>>> Python 3.3.0 should be released around September 22. I would like to
>>> take this opportunity to implement some of the recommendations of the
>>> PEP 394 [1]. This PEP was mostly done in reaction to what Arch did to
>>> the /usr/bin/python symlink (in summary, most python devs are against
>>> the move to python3 as a default at this time).
>>>
>>> In short:
>>> python2 should refer to some version of Python 2.x
>>> python3 should refer to some version of Python 3.x
>>> python should refer to the same target as python2 but may refer to
>>> python3 on some bleeding edge distributions
>>>
>>> This means that we should never have a reference to '#!/usr/bin/python'
>>> in any of our packages. All those reference should be changed to
>>> /usr/bin/python2 to refer to Python 2.x and /usr/bin/python3 for Python
>>> 3.x. The idea here is that a system without any python symlink should
>>> work without problem. Maybe namcap could be used to detect wrong shebang ?
>>
>> This is necessary as far as I am concerned.
> 
> And you have also been mentioning this from as far back as I can
> remember since the move. Therefore I would assume this is not (going
> to be) a problem if we have been listening.
> 
> So now do we simply remove the python symlink and leave it up to the users?
> 

No.  We keep it as python -> python3.  The user can change it to point
it at python2 if they want but given we have no alternatives system in
pacman, it will revert on python3 upgrades.  Maybe something to implement...

Allan