Red Nose Hacker

When I edit Guile code in Emacs, there are some tools relying on the environment to work (i.e. Emacs extensions like Geiser, Flycheck-Guile). Parts of this environment are project specific while others are shared across projects. So I ended up setting manually my environment usually following these few steps:

$ guix shell guile
$ export GUILE_LOAD_PATH="$PWD:$GUILE_LOAD_PATH$
$ emacs some-script.scm

I did turn it into a script I cast as a spell but still, I wanted to go further. And one day…

I read this thread from a Guix mailing list. Almost what I am looking for, a bit rough.

And later this post from David Thompson's blog. Which lead me to the Gitlab account of Andrew Whatson with use cases.

They paved the way. I feel I can give it a try.

David wrote about direnv.el which run all the things starting from Emacs in the environment made by direnv.

So let's go!

$ guix install direnv emacs-direnv

At the end of my .bashrc:

eval "$(direnv hook bash)"

In my Emacs configuration:

(use-package direnv
 :config
 (direnv-mode))

Finally, inside the .envrc file of your simple Guile project:

eval $(guix shell guile --search-paths)
export GUILE_LOAD_PATH="$PWD:$GUILE_LOAD_PATH="

Now all you need to do is fire Emacs up, open a file from one of your Guile project and taste the fun.

Oh wait! If you are like me, you may open several files from different projects to copy/paste, evaluate s-expressions, whatever… The thing is, the actual Emacs environment is the one from the first file opened. Too bad.

Fortunately, Steve Purcell already solved the problem with envrc.el ! Let's make the switch.

$ guix remove emacs-direnv
$ guix install emacs-envrc

And also substitute envrc.el from direnv.el in your Emacs configuration:

(use-package envrc
 :config
 (envrc-global-mode))

Let me know how it feels ;)

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