Add guix.scm package recipe.

* guix.scm: New file.

guix.scm

@@ -0,0 +1,84 @@
+;;; guix.scm -- Guix package definition
+
+;;; Mes --- Maxwell Equations of Software
+;;; Copyright © 2016 Jan Nieuwenhuizen <janneke@gnu.org>
+;;;
+;;; guix.scm: This file is part of Mes.
+;;;
+;;; Mes is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; Mes is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with Mes.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;; GNU Guix development package.  To build and install, run:
+;;
+;;   guix package -f guix.scm
+;;
+;; To build it, but not install it, run:
+;;
+;;   guix build -f guix.scm
+;;
+;; To use as the basis for a development environment, run:
+;;
+;;   guix environment -l guix.scm
+;;
+;;; Code:
+
+(use-modules (gnu packages)
+             (gnu packages base)
+             (gnu packages guile)
+             (gnu packages package-management)
+             (gnu packages perl)
+             (gnu packages version-control)
+             (guix git-download)
+             (guix licenses)
+             (guix packages)
+             (guix build-system gnu))
+
+(define-public mes
+  (package
+    (name "mes")
+    (version "0.0.e471916")
+    (source (origin
+              (method git-fetch)
+              (uri (git-reference
+                    (url "https://gitlab.com/janneke/mes")
+                    (commit "master")))
+              (sha256
+               (base32
+                "1rczxfap2d51hl619laxj3qfp89kq22sy79329kdd324nxzm3na0"))))
+    (build-system gnu-build-system)
+    (native-inputs
+     `(("git" ,git)
+       ("guile" ,guile-2.0)
+       ("perl" ,perl)))                ; build-aux/gitlog-to-changelog
+    (arguments
+     `(#:phases
+       (modify-phases %standard-phases
+         (add-before 'install 'generate-changelog
+           (lambda _
+             (with-output-to-file "ChangeLog"
+               (lambda ()
+                 (display "Please run\n  build-aux/gitlog-to-changelog --srcdir=<git-checkout> > ChangeLog\n")))
+             #t)))))
+    (synopsis "Maxwell Equations of Software")
+    (description
+     "Mes aims to create an entirely source-based bootstrapping path.
+The target is to [have GuixSD] boostrap from a minimal, easily
+inspectable binary --that should be readable as source-- into
+something close to R5RS Scheme.")
+    (home-page "https://gitlab.com/janneke/mes")
+    (license gpl3+)))
+
+;; Return it here so 'guix build/environment/package' can consume it directly.
+mes