Re: [PATCH] build: ruby: Patch executables to set necessary gem load path.

[Ludovic Courtès]

David Thompson <address@hidden> skribis:

> This patch addresses the issue of how to ensure that Ruby executables
> are able to load all of the additional Ruby libraries that they need in
> order to work: with a new 'patch-executables' build phase.  Instead of
> using wrap-program, I instead take advantage of the wrappers that the
> 'gem' command already creates for Ruby executables.  There's guaranteed
> to be a line in which the executable's host gem is loaded that looks
> like `gem 'foo', version`.  I simply insert a Ruby code snippet above it
> that adds all of the necessary gems to the 'Gem.path' array.

OK.

> Users of Ruby programs must still apply the $GEM_PATH suggested by 'guix
> package --search-paths' in order for the gem that the executable belongs
> to (the gem that they explicitly installed) to be found.  I think this
> is reasonable and much like how you must set the proper load paths for
> Guile programs to work.

Makes sense.

> From 614fedc2b359f123dfdf4e31eee30e7ce47e1bd2 Mon Sep 17 00:00:00 2001
> From: David Thompson <address@hidden>
> Date: Sat, 7 Mar 2015 18:39:52 -0500
> Subject: [PATCH] build: ruby: Patch executables to set necessary gem load
>  path.
>
> * guix/build/ruby-build-system.scm (gem-directory): New procedure.
>   (install): Deduplicate gem directory code.
>   (patch-executables): New procedure.
>   (%standard-phases): Add 'patch-executables' phase.

[...]

> +(define* (patch-executables #:key inputs outputs #:allow-other-keys)

Please add a docstring, with the rationale you gave in this message as
part of the docstring or in a comment.

OK to push with this change, thank you!

Ludo’.