bug#27572: simultaneous installation of python2 and python3 fails

bug#27572: simultaneous installation of python2 and python3 fails

[Diego Nicola Barbato]

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

This error could be reproduced in a VM created with guix system vm-image
and following config file:

  (use-modules (gnu) (gnu packages) (gnu system nss))
  (use-service-modules desktop xorg)
  (use-package-modules certs gnome xdisorg lisp)

  (operating-system
   (host-name "Test")
   (timezone "Europe/Zurich")
   (locale "de_CH.UTF-8")

   (bootloader (grub-configuration (device "/dev/sda")
                                   (timeout 1)))

   (file-systems (cons (file-system
                        (mount-point "/")
                        (device "/dev/sda1")
                        (type "ext4"))
                       %base-file-systems))

   (users (cons (user-account
                 (name "user1")
                 (comment "User")
                 (group "users")
                 (supplementary-groups '("wheel" "audio" "video"))
                 (home-directory "/home/user1"))
                %base-user-accounts))

   (packages (cons* nss-certs
                    sbcl-stumpwm (list sbcl-stumpwm "lib")
                    %base-packages))

   (services (cons* (screen-locker-service xscreensaver "xscreensaver")
                    (console-keymap-service "de_CH-latin1")
                    %desktop-services))

   (name-service-switch %mdns-host-lookup-nss))

bug#27572: simultaneous installation of python2 and python3 fails

[Ludovic Courtès]

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?

Thanks,
Ludo’.

bug#27572: simultaneous installation of python2 and python3 fails

[Diego Nicola Barbato]

Hello Ludo,

Thanks for your reply.

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.

> Thanks,
> Ludo’.

Greetings

Diego

bug#27572: simultaneous installation of python2 and python3 fails

[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’.