On Fri, 12 Jun 2020, Josh Marshall wrote:

> Hello all,
>
> I ran into an issue where the readline module isn't available for the
> guile repl after installing `guile-readline`.  It can be replicated
> via:
>
> `echo "(use-modules (ice-9 readline))" | guix environment --pure guile
> guile-readline -- guile`
>
> So with that, I'm pretty sure it isn't just me.

I think you actually want to be using a different guix environment
command.

guix environment --pure --ad-hoc guile guile-readline

should get you what you want. The difference is that without --ad-hoc,
what you're asking for is an environment with all the dependencies of
guile and guile-readline. This is useful, for instance, if you want to
work on those packages. In this case, guile is available because
guile-readline depends on it, but nothing depends on guile-readline, so it
is not in the environment.

With --ad-hoc, you specify the the packages you want in the environment
explicitly.

See the manual [0] for more information and more advanced usage of
environment.

[0] https://guix.gnu.org/manual/en/html_node/Invoking-guix-environment.html

This isn't the first time the --ad-hoc has caused confusion. I tend to use
that option more often than not. There was previous discussion [1] about
making environment more friendly to use interactively without breaking
compatibility, but more work is still needed on that front.

[1] https://lists.gnu.org/archive/html/guix-devel/2019-12/msg00126.html

Hope that helps,
Jack