Whoops, geiser-user@ doesn't exist.  But geiser-users@ supposedly does.
I meant to send this email there, so I will try again.  Email follows:

Chris Marusich <cmmarusich@gmail.com> writes:

> Hi,
>
> It seems that geiser-xref-callers does not work for me.  I believe I've
> configured Geiser correctly, since other commands like
> geiser-edit-symbol-at-point and geiser-doc-symbol-at-point do work in
> some cases.
>
> Here is a specific example where it fails for me:
>
> * Clone the Guix Git repository (for commit
>   9e111db4535b3cd5729e37294ae51d95240334b4 if you want to be precise):
>
>     git clone https://git.savannah.gnu.org/git/guix.git
>
> * Configure Geiser for Guix as described in Guix's manual ((guix) The
>   Perfect Setup).
>
> * Open gnu/system/vm.scm in the Guix source tree, and run
>   switch-to-geiser-module for the (gnu system vm) module.
>
> * Place point on symbol expression->derivation-in-linux-vm on line 203
>   (in the definition of the iso9660-image procedure), and press "C-c <".
>
> When I do this, I receive the following message in the minibuffer:
>
>   No callers found for ’expression->derivation-in-linux-vm’
>
> And yet, if I run "M-x rgrep" on the same symbol, there are obviously
> many call sites:
>
>   ./gnu/system/vm.scm:68:  #:export (expression->derivation-in-linux-vm
>   ./gnu/system/vm.scm:105:(define* (expression->derivation-in-linux-vm name exp
>   ./gnu/system/vm.scm:203:  (expression->derivation-in-linux-vm
>   ./gnu/system/vm.scm:274:  (expression->derivation-in-linux-vm
>
> What might the problem be?  When I run "M-x geiser-doc-symbol-at-point"
> on this symbol, it also claims that there is no documentation
> available.  I feel like maybe I've misconfigured something, but I don't
> know what.
>
> Here are the Geiser-specific things I've added to my ~/.emacs file:
>
> ;; Tell geiser where guix checkout lives
> (with-eval-after-load 'geiser-guile
>                       (add-to-list 'geiser-guile-load-path "~/guix"))
>
> (add-hook 'geiser-repl-mode-hook 'enable-paredit-mode)
>
> ;; Keybind customizations
> (add-hook 'geiser-mode-hook
>           (lambda ()
>             (local-set-key (kbd "C-c m") 'switch-to-geiser-module)))
> (add-hook 'geiser-mode-hook
>           (lambda ()
>             (local-set-key (kbd "C-c i") 'geiser-repl-import-module)))

-- 
Chris