bug#27572: simultaneous installation of python2 and python3 fails

[ludo@gnu.org (Ludovic Courtès)]

Hi Diego,

Diego Nicola Barbato <dnbarbato@posteo.de> skribis:

> ludo@gnu.org (Ludovic Courtès) writes:
>
>> Hello Diego,
>>
>> Diego Nicola Barbato <dnbarbato@posteo.de> skribis:
>>
>>> When running the command "guix pull && guix package -i python@2 python"
>>> instead of installing the latest version of python2 and python3, as it
>>> used to do until about four weeks ago, guix gives following error
>>> message (hash values replaced with ...):
>>>
>>>   guix package: error: profile contains conflicting entries for python:out
>>>   guix package: error:   first entry: python@2.7.13:out /gnu/store/...-python-2.7.13
>>>   guix package: error:   second entry: python@3.5.3:out /gnu/store/...-python-3.5.3
>>
>> Indeed, Guix now refuses to install two different versions or variants
>> of the same package since in general they would conflict.
>>
>> In this particular case, they do not actually conflict, I think, since
>> python@3 provides executables prefixed by “3” whereas python@2 does not.
>>
>> Perhaps we should rename “python” to “python2” or something like that?
>>
>> In the meantime, I recommend using separate profiles for your Python 2
>> and Python 3 development environments.  Is that a viable option for you?
>
> Using separate profiles seems like a reasonable option. I also tried
> using guix environment with the --ad-hoc flag.

Right, that should work fine.

I’m closing this bug now; please do reopen it if you feel like the
solutions above aren’t quite convenient after all.

Thank you,
Ludo’.