bug#48082: “guix environment -l” does not work with inferior packages

[Ricardo Wurmus]

I wanted to use an environment file that contains a package 
definition, and use it with inferiors.  Here is the full guix.scm:

--8<---------------cut here---------------start------------->8---
(use-modules
(guix channels)
(guix inferior)
(guix build-system gnu)
(guix packages)
(guix licenses)
(gnu packages)
(ice-9 match))

(define channels
 (list (channel
        (name 'guix-bimsb)
        (url "https://github.com/BIMSBbioinfo/guix-bimsb.git";)
        (commit
         "be42b099867a29a68a9ffbf304dc7f9137b75fe3"))
       (channel
        (name 'guix)
        (url "https://git.savannah.gnu.org/git/guix.git";)
        (commit
         "01e33a031e493477d930b9383d397fea012a3b1a")
        (introduction
         (make-channel-introduction
          "9edb3f66fd807b096b48283debdcddccfea34bad"
          (openpgp-fingerprint
           "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 
           54FA"))))))

(define (lookup name)
 (specification->package name))

(define (lookup-inferior name)
 (define inferior
   (inferior-for-channels channels))
 (match (lookup-inferior-packages inferior name)
   ((first . rest) first)
   (_ (error
       (format #false "Could not find package `~a'.~%" name)))))

(define (p name)
 (let* ((how (if (getenv "USE_GUIX_INFERIOR")
                 lookup-inferior lookup))
        (pkg (how name)))
   `(,name ,pkg)))

(define %version
 (symbol->string (with-input-from-file "VERSION" read)))

(define-public my-package
 (package
   (name "my-package")
   (version %version)
   (source
    (string-append (getcwd) "/my-package-" version ".tar.gz"))
   (build-system gnu-build-system)
   (inputs
    (map p (list "bwa"
                 "r-minimal"
                 "r-rmarkdown"
                 "python-wrapper"
                 "python-pyyaml")))
   (native-inputs
    (map p (list "autoconf"
                 "automake")))
   (home-page "TODO")
   (synopsis "TODO")
   (description "TODO")
   (license gpl3+)))

my-package
--8<---------------cut here---------------end--------------->8---

The idea was that you would use the provided channels with

   USE_GUIX_INFERIOR=t guix environment -l guix.scm

Unfortunately, this does not work, but there also is no error.  I 
end up in an environment where none of the declared inputs are 
available.  That’s because (guix scripts environments) has no 
facilities to deal with packages that are of type 
<inferior-package>.

--
Ricardo