guix-bavier/build-aux/list-packages.sh

#!/bin/sh
export COLUMNS=80
moduledir="${1:-$(pwd)}"
guile -L "$moduledir" \
      -c '
(use-modules (guix discovery)
             (guix ui)
             (gnu packages)
             (srfi srfi-26))
(define modules
  (fold-modules cons (list) (list "'"$moduledir"'")))
(define packages
  (fold-packages cons (list) modules))
(for-each
   (cute package->recutils <> (current-output-port))
   packages)
'