Re: [PATCH] python: prioritize python 3.x over 2.x

Zack Weinberg wrote:
> On Wed, Jan 26, 2022, at 10:10 PM, Mike Frysinger wrote:
>   
>> On 26 Jan 2022 10:07, Zack Weinberg wrote:
>>     
>>> Please also move the plain "python" command down to the python2
>>> block (right after "python2" would be the best place I think).  Any
>>> system on which "python" runs Python 3 is grossly misconfigured.
>>>       
>> i don't think that's accurate.  Python PEP-0394 explicitly permits
>> `python` to be any version, and many distros do just that
>>     
>
> Yes, I know.  PEP 394 is wrong.  Its authors grossly underestimated
> the volume of Python 2 code that still exists today and, if
> accidentally executed with a v3 interpreter, will *silently*
> malfunction -- not just crashing, but corrupting data with no warning.
> I had to deal with this kind of code all the time in my previous day
> job and I'm still quite peeved that the Python devs blew me off about it.
>
> What PEP 394 *should* have said is that the command name "python" and
> the #! path /usr/bin/python MUST[rfc2119] be *permanently reserved*
> for the Python 2.7 interpreter, and "python3" is the only acceptable
> not-specifically-versioned command name for the 3.x interpreter, even
> in virtualenvs.
>
>   
>> distros that remove `python` entirely as part of Python 2 removal
>> are doing it wrong.
>>     
>
> On the contrary, those distros are the only ones doing it right.
>
> Now, nobody listens to me, and I'm painfully aware that "python"
> pointing to Python 3 is common, but that doesn't mean Autotools should
> make the situation even worse.  Autotools should, on its own motion,
> discourage the use of "python".  Thus, my suggested changes.
>   

Are Python 2 and Python 3 different enough that perhaps Automake should 
have separate AM_PATH_PYTHON2 and AM_PATH_PYTHON3 macros, with 
AM_PATH_PYTHON deprecated, since few programs can usefully run with 
either Python 2 or 3?

In other words, are we conflating two features behind "PYTHON" that are 
actually logically separate?


-- Jacob