Sorry about that, guix didn't complain at compile time and every looked
fine, but apparently I missed something :(

On closer look, I think I found the culprit: we have a minify build
system and in guix/build-system/minify.scm we define the
default-uglify-js procedure which retrieves uglify-js from the lisp
module.

I assume the following would do the trick:

--8<---------------cut here---------------start------------->8---
(define (default-uglify-js)
  "Return the default package to minify JavaScript source files."
  ;; Lazily resolve the binding to avoid a circular dependency.
  (let ((js-mod (resolve-interface '(gnu packages javascript))))
    (module-ref js-mod 'uglify-js)))
--8<---------------cut here---------------end--------------->8---

Does that sound reasonable?
Ricardo?

By the way, is there a convenient way to catch this kind of errors
without pushing to master first?

-- 
Pierre Neidhardt
https://ambrevar.xyz/