How to get Guix perfect setup to work

The official Guix documentation describes [The Perfect Setup](https://guix.gnu.org/manual/en/html_node/The-Perfect-Setup.html) for hacking on Guix. I have followed this description and set up everything like described, but still Geiser does not work fully. I thought that this was supposed to give me completion capabilities and make it possible to go to the definition of things. I can go to definition of some things, but only very few. Most things is not possible. Completion seems to be only based on text in the current buffer. # My Emacs configurations

(use-package geiser
  :ensure t
  :custom
  (geiser-default-implementation 'guile)
  (geiser-active-implementations '(guile))
  (geiser-implementations-alist '(((regexp "\\.scm$") guile))))

(use-package geiser-guile
  :ensure t
  :config
  (add-to-list 'geiser-guile-load-path "/home/lars/code/forks/guix")
  (add-to-list 'geiser-guile-load-path "/home/lars/code/guix/modules")
  (add-to-list 'geiser-guile-load-path "/home/lars/code/guix"))

(with-eval-after-load "geiser-guile" 
  (add-to-list 'geiser-guile-load-path "/home/lars/code/forks/guix")
  (add-to-list 'geiser-guile-load-path "/home/lars/code/guix/modules")
  (add-to-list 'geiser-guile-load-path "/home/lars/code/guix"))

# REPL I invoke the Geiser REPL in Emacs with M-x geiser-guile or M-x geiser. The output in the Geiser REPL looks like this:

GNU Guile 3.0.9
Copyright (C) 1995-2023 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)>

Note that the prompt says guile-user, but I think it should say guix-user. However, if I start the Guix REPL by running guix repl in a terminal the output looks like this:

GNU Guile 3.0.9
Copyright (C) 1995-2023 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guix-user)>

Note that here it says guix-user. When trying to 'use' the guix module in Geiser REPL:

,use (guix)
;;; note: auto-compilation is enabled, set GUILE_AUTO_COMPILE=0
;;;       or pass the --no-auto-compile argument to disable.
;;; compiling /home/lars/code/forks/guix/guix.scm
;;; compiling /home/lars/code/forks/guix/guix/packages.scm
;;; compiling /home/lars/code/forks/guix/guix/utils.scm
;;; WARNING: compilation of /home/lars/code/forks/guix/guix/utils.scm failed:
;;; no code for module (guix config)
;;; WARNING: compilation of /home/lars/code/forks/guix/guix/packages.scm failed:
;;; no code for module (guix config)
;;; compiling /home/lars/code/forks/guix/guix/store.scm
;;; WARNING: compilation of /home/lars/code/forks/guix/guix/store.scm failed:
;;; no code for module (guix config)
;;; WARNING: compilation of /home/lars/code/forks/guix/guix.scm failed:
;;; no code for module (guix config)
;;; compiling /home/lars/code/forks/guix/guix/derivations.scm
;;; compiling /home/lars/code/forks/guix/guix/diagnostics.scm
;;; WARNING: compilation of /home/lars/code/forks/guix/guix/diagnostics.scm failed:
;;; Unbound variable: trivial-format-string?
;;; WARNING: compilation of /home/lars/code/forks/guix/guix/derivations.scm failed:
;;; no code for module (gcrypt hash)
While executing meta-command:
no code for module (gcrypt hash)
scheme@(guile-user)>

Doing the same in a Guix REPL works fine:

scheme@(guix-user)> ,use (guix)
scheme@(guix-user)>

# Go to definition Go to definition works in some places, for example in the line below:

(gnu home services)

This takes me correctly to the source of gnu home services. However, trying to go to the definition of packages does not work:

(packages (list
            htop
            git
            alacritty
            tmux))

Trying to go to the definition of any of the packages in the package list just does not work. # Completion I would expect to be able to get completions for modules and packages (among other things) by typing the start of the name of the packages, but nothing comes. Sometimes I get some random completion based on random text in the same buffer, but most of the time not even that.