Yes, this is *exactly* what I was looking for. Thanks incredibly.
It took me a while to realize that the package module for racket was "scheme". I figured this out after getting an error with "racket", and then looking at the "location" field of the output of `guix package -s racket`. I assume the package module for any package is the last token in "gnu/modules/<package-here>.scm? Are there packages not rooted in "gnu/modules"?
Is there more documentation on manifest files? It would be really helpful to, for example, be able to see the definition of `use-package-modules` or `packages->manifest`. Is this information I can access in Emacs through geiser? Or perhaps a webpage with more such information? Thanks.