Dealing with environment settings on a non-Guix distribution

[Pjotr Prins <pjotr.public12@thebird.nl>]

Dear Ricardo,

@FOSDEM one thing came up that we ought to make it easier to handle
environment settings (shell variables). Yesterday, I had to help
somenone use R and install some packages in $HOME. This proved quite
hairy. Mostly because we needed to tell R about certificates in
/etc/ssl, change the native download from curl to wget, and to tell R
about library paths for dependencies on openssl, for example. Not
something you'd like a non-guixer try to figure out.

For Ruby I created a script in 

  https://github.com/pjotrp/guix-notes/blob/master/scripts/ruby-guix-env

(actually it is out of date, I also deal with certificates).

I think we can have more of these 'environment' managing scripts. Can
we somehow get them into Guix? Maybe create a separate package for
each of them - say ruby-guix-env and r-guix-env? It would help
bootstrap people using Guix for R, ruby and other languages.

Pj.