bug#30437: No “.guix-profile/bin/python” after ‘guix package -i python’

bug#30437: No “.guix-profile/bin/python” after ‘guix package -i python’

[Mathieu Lirzin]

Hello,

I think it would work better if when installing python@3, a ‘python’
executable would be available in the PATH.  Maybe there is a technical
reason for not doing so, but I find its absence rather confusing.

Thanks for considering it.

-- 
Mathieu Lirzin
GPG: F2A3 8D7E EB2B 6640 5761  070D 0ADE E100 9460 4D37

bug#30437: No “.guix-profile/bin/python” after ‘guix package -i python’

[Danny Milosavljevic]

Hi Mathieu,

On Mon, 12 Feb 2018 17:52:41 +0100
Mathieu Lirzin <mthl@gnu.org> wrote:

> I think it would work better if when installing python@3, a ‘python’
> executable would be available in the PATH.  Maybe there is a technical
> reason for not doing so, but I find its absence rather confusing.

For backward compatibility, the 'python' executable always has to be Python 2.

A lot of old scripts specify just "/usr/bin/env python" in the shebang.

On the other hand if your script supports Python 3 you know it.

bug#30437: No “.guix-profile/bin/python” after ‘guix package -i python’

[Efraim Flashner]

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On Mon, Feb 12, 2018 at 06:23:07PM +0100, Danny Milosavljevic wrote:
> Hi Mathieu,
> 
> On Mon, 12 Feb 2018 17:52:41 +0100
> Mathieu Lirzin <mthl@gnu.org> wrote:
> 
> > I think it would work better if when installing python@3, a ‘python’
> > executable would be available in the PATH.  Maybe there is a technical
> > reason for not doing so, but I find its absence rather confusing.
> 
> For backward compatibility, the 'python' executable always has to be Python 2.
> 
> A lot of old scripts specify just "/usr/bin/env python" in the shebang.
> 
> On the other hand if your script supports Python 3 you know it.
> 

We do also have the 'python-wrapper' package which uses python3 as
python

-- 
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bug#30437: No “.guix-profile/bin/python” after ‘guix package -i python’

[Ricardo Wurmus]

Efraim Flashner <efraim@flashner.co.il> writes:

> On Mon, Feb 12, 2018 at 06:23:07PM +0100, Danny Milosavljevic wrote:
>> Hi Mathieu,
>> 
>> On Mon, 12 Feb 2018 17:52:41 +0100
>> Mathieu Lirzin <mthl@gnu.org> wrote:
>> 
>> > I think it would work better if when installing python@3, a ‘python’
>> > executable would be available in the PATH.  Maybe there is a technical
>> > reason for not doing so, but I find its absence rather confusing.
>> 
>> For backward compatibility, the 'python' executable always has to be Python 2.
>> 
>> A lot of old scripts specify just "/usr/bin/env python" in the shebang.
>> 
>> On the other hand if your script supports Python 3 you know it.
>> 
>
> We do also have the 'python-wrapper' package which uses python3 as
> python

Closing because it’s not a bug.

-- 
Ricardo

GPG: BCA6 89B6 3655 3801 C3C6  2150 197A 5888 235F ACAC
https://elephly.net

bug#30437: No “.guix-profile/bin/python” after ‘guix package -i python’

[Mathieu Lirzin]

Hi,

Danny Milosavljevic <dannym@scratchpost.org> writes:

> On Mon, 12 Feb 2018 17:52:41 +0100
> Mathieu Lirzin <mthl@gnu.org> wrote:
>
>> I think it would work better if when installing python@3, a ‘python’
>> executable would be available in the PATH.  Maybe there is a technical
>> reason for not doing so, but I find its absence rather confusing.
>
> For backward compatibility, the 'python' executable always has to be Python 2.
>
> A lot of old scripts specify just "/usr/bin/env python" in the shebang.
>
> On the other hand if your script supports Python 3 you know it.

Hum, then I don't understand why we aren't applying this argument to
every interperter (Perl, Guile, ...) which introduce backward
incompatible changes?

-- 
Mathieu Lirzin
GPG: F2A3 8D7E EB2B 6640 5761  070D 0ADE E100 9460 4D37

bug#30437: closed (Re: bug#30437: No “.guix-profile/bin/python” after ‘guix package -i python’)

[Mathieu Lirzin]

help-debbugs@gnu.org (GNU bug Tracking System) writes:

> From: Ricardo Wurmus <rekado@elephly.net>
> Subject: Re: bug#30437: No “.guix-profile/bin/python” after ‘guix package -i python’
> To: 30437-done@debbugs.gnu.org
> Date: Mon, 12 Feb 2018 20:00:57 +0100 (38 minutes, 1 second ago)
> User-agent: mu4e 0.9.18; emacs 25.3.1
>
>
> Efraim Flashner <efraim@flashner.co.il> writes:
>
>> On Mon, Feb 12, 2018 at 06:23:07PM +0100, Danny Milosavljevic wrote:
>>> Hi Mathieu,
>>> 
>>> On Mon, 12 Feb 2018 17:52:41 +0100
>>> Mathieu Lirzin <mthl@gnu.org> wrote:
>>> 
>>> > I think it would work better if when installing python@3, a ‘python’
>>> > executable would be available in the PATH.  Maybe there is a technical
>>> > reason for not doing so, but I find its absence rather confusing.
>>> 
>>> For backward compatibility, the 'python' executable always has to be Python 2.
>>> 
>>> A lot of old scripts specify just "/usr/bin/env python" in the shebang.
>>> 
>>> On the other hand if your script supports Python 3 you know it.
>>> 
>>
>> We do also have the 'python-wrapper' package which uses python3 as
>> python

It is nice to have a ‘python-wrapper’ package as a workaround, but this
doesn't explain why the ‘python’ package shouldn't do it automatically.
Doing so would be far more convenient for casual users.

> Closing because it’s not a bug.

IMHO that was a bit quick to close.  I still consider this as a wishlist
bug.

-- 
Mathieu Lirzin
GPG: F2A3 8D7E EB2B 6640 5761  070D 0ADE E100 9460 4D37

bug#30437: No “.guix-profile/bin/python” after ‘guix package -i python’

[Ricardo Wurmus]

Mathieu Lirzin <mthl@gnu.org> writes:

> Hi,
>
> Danny Milosavljevic <dannym@scratchpost.org> writes:
>
>> On Mon, 12 Feb 2018 17:52:41 +0100
>> Mathieu Lirzin <mthl@gnu.org> wrote:
>>
>>> I think it would work better if when installing python@3, a ‘python’
>>> executable would be available in the PATH.  Maybe there is a technical
>>> reason for not doing so, but I find its absence rather confusing.
>>
>> For backward compatibility, the 'python' executable always has to be Python 2.
>>
>> A lot of old scripts specify just "/usr/bin/env python" in the shebang.
>>
>> On the other hand if your script supports Python 3 you know it.
>
> Hum, then I don't understand why we aren't applying this argument to
> every interperter (Perl, Guile, ...) which introduce backward
> incompatible changes?

As far as I know, the Python 3 package does not provide the “python”
binary.  That’s upstream’s decision.

-- 
Ricardo

GPG: BCA6 89B6 3655 3801 C3C6  2150 197A 5888 235F ACAC
https://elephly.net

bug#30437: No “.guix-profile/bin/python” after ‘guix package -i python’

[Mathieu Lirzin]

Ricardo Wurmus <rekado@elephly.net> writes:

> Mathieu Lirzin <mthl@gnu.org> writes:
>
>> Danny Milosavljevic <dannym@scratchpost.org> writes:
>>
>>> On Mon, 12 Feb 2018 17:52:41 +0100
>>> Mathieu Lirzin <mthl@gnu.org> wrote:
>>>
>>>> I think it would work better if when installing python@3, a ‘python’
>>>> executable would be available in the PATH.  Maybe there is a technical
>>>> reason for not doing so, but I find its absence rather confusing.
>>>
>>> For backward compatibility, the 'python' executable always has to be Python 2.
>>>
>>> A lot of old scripts specify just "/usr/bin/env python" in the shebang.
>>>
>>> On the other hand if your script supports Python 3 you know it.
>>
>> Hum, then I don't understand why we aren't applying this argument to
>> every interperter (Perl, Guile, ...) which introduce backward
>> incompatible changes?
>
> As far as I know, the Python 3 package does not provide the “python”
> binary.  That’s upstream’s decision.

Indeed your are right, they provide no configure option to enable such
thing as they don't encourage downstream to use ‘python’ as an alias to
‘python3’ yet.  After some research this is discussed in PEP-0394. [1]

As a consequence it seems reasonable for Guix to not deviate from
upstream recommandation, even if the shebang issue described by PEP-0394
are mitigated by the functional package management paradigm.

Thanks.

[1] https://www.python.org/dev/peps/pep-0394/

-- 
Mathieu Lirzin
GPG: F2A3 8D7E EB2B 6640 5761  070D 0ADE E100 9460 4D37