bug#46803: User manual does not explain Profiles (nor GUIX_PROFILE)

[zimoun]

Hi Tobias,

On Sat, 27 Feb 2021 at 00:30, Tobias Geerinckx-Rice via Bug reports for GNU 
Guix <bug-guix@gnu.org> wrote:

> Out of curiosity: how do you intuitively understand profiles, as 
> someone who's used Guix for a while?

Effectively, profiles is not explicitly defined but implicitly, for
instance:

<https://guix.gnu.org/manual/devel/en/guix.html#Features>

Otherwise, the most explicit definition is in the Cookbook:

        Guix provides a very useful feature that may be quite foreign to
        newcomers: profiles. They are a way to group package
        installations together and all users on the same system are free
        to use as many profiles as they want.

<https://guix.gnu.org/cookbook/en/html_node/Guix-Profiles-in-Practice.html>


BTW, I remember that coming from Conda (and Python), I was confused by
what was Profile and Environment in Guix, since ’environment’ (in Conda)
corresponds to Profile (in Guix).  Anyway, for words inspiration,
Conda’s doc:

        A conda environment is a directory that contains a specific collection
        of conda packages that you have installed. For example, you may have one
        environment with NumPy 1.7 and its dependencies, and another environment
        with NumPy 1.6 for legacy testing. If you change one environment, your
        other environments are not affected. You can easily activate or
        deactivate environments, which is how you switch between them. You can
        also share your environment with someone by giving them a copy of your
        environment.yaml file. For more information, see Managing environments.

<https://docs.conda.io/projects/conda/en/latest/user-guide/concepts/environments.html>

And from this old time, I remember that examples really helps, for
instance.

<https://docs.conda.io/projects/conda/en/latest/user-guide/getting-started.html#managing-environments>.

Therefore, the section «Getting Started» could be a bit extended with a
paragraph about Profiles and one or two examples.  WDYT?

<https://guix.gnu.org/manual/devel/en/guix.html#Getting-Started>


Cheers,
simon