Re: guix build reports "unknown package" when building own package.

[Tobias Geerinckx-Rice]

…as for use-modules: yes, (USE-MODULES LIST) is a thing, but *not* as an 
argument to DEFINE-MODULE:

  (define-module NAME [KEYWORD-ARGUMENT…])

vs.

  (define-module NAME)
  (use-modules LIST)

By nesting USE-MODULES *within* the sweet embrace of DEFINE-MODULES, you were 
attempting to combine the two, into an unholy abomination that means nothing.

I know, it's confusing, but just treat it as an opaque rule until you get used 
to it.

Kind regards,

T G-R

Sent on the go.  Excuse or enjoy my brevity.