Guix completion in Emacs

[Kyle Andrews]

Hello Everyone,

I am unable to conditional tab completion of Guix commands when in
shell-mode or eshell-mode in Emacs. In other words, I can tab-complete
the major modules e.g. ~guix package~, but cannot tab complete
~--arguments~ to them. When I try I see an error:

  guix-geiser-eval: Error in evaluating guile expression: 
ice-9/boot-9.scm:1669:16: In procedure raise-exception:
  error: help-string: unbound variable

Certainly this stuff isn't broken for everyone, is it?