Geiser can be configured to read ~/.guile when running Guile from within Emacs. I would like to append command line options to the argument list passed to guile.
Is there a variable that holds the command line options?
Customize geiser-guile-binary to a list of strings (change the "Value" button to "repeat"). The first one should be "guile" (or whatever the binary for guile is on your system) and the next entries should be strings each containing one argument.
You can double check it by putting (insert (pp (geiser-guile--parameters))) in a scheme file with geiser loaded and then running M-x eval-last-sexp.