Thaddäus Töppen <thaddaeus.toeppen@gmail.com> writes:
> Am I correct in assuming, that only one manifest file can be installed at a
> time, thus all package definitions have to be in one file (or at least
> imported into a main-package-file)?

Yes, but since manifest file is a Guile program, you can implement any
custom logic for constructing the manifest there.

Here is an example of a manifest file that loads multiple manifests and
composes them into one:

----------------------------------------------------------------------
(use-modules (srfi srfi-1)
             ((guix ui) #:select (make-user-module)))

(define (load-manifest file)
  ;; Load manifest file in a fresh module with necessary imports.
  (let ((module (make-user-module '((guix profiles) (gnu)))))
    (save-module-excursion
     (lambda _
       (set-current-module module)
       (load (canonicalize-path file))))))

(define (combined-manifest-from-files . files)
  (fold (lambda (file combined)
          (manifest-add combined
                        (manifest-entries (load-manifest file))))
        (manifest '())
        files))

(combined-manifest-from-files
 "emacs.scm"
 "xorg.scm"
 "etc.scm")
----------------------------------------------------------------------

-- 
Mikhail