Add (guix git-download).

* guix/git-download.scm, guix/build/git.scm: New files.
* Makefile.am (MODULES): Add them.
* guix/packages.scm (<origin>): Fix comment for 'method' field.

1 files changed, 45 insertions, 0 deletions

diff --git a/guix/build/git.scm b/guix/build/git.scm
new file mode 100644
index 0000000000..4245594c38
--- /dev/null
+++ b/guix/build/git.scm
@@ -0,0 +1,45 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2014 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix 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.
+;;;
+;;; GNU Guix 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 GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix build git)
+  #:use-module (guix build utils)
+  #:export (git-fetch))
+
+;;; Commentary:
+;;;
+;;; This is the build-side support code of (guix git-download).  It allows a
+;;; Git repository to be cloned and checked out at a specific commit.
+;;;
+;;; Code:
+
+(define* (git-fetch url commit directory
+                    #:key (git-command "git"))
+  "Fetch COMMIT from URL into DIRECTORY.  COMMIT must be a valid Git commit
+identifier.  Return #t on success, #f otherwise."
+  (and (zero? (system* git-command "clone" url directory))
+       (with-directory-excursion directory
+         (system* git-command "tag" "-l")
+         (and (zero? (system* git-command "checkout" commit))
+              (begin
+                ;; The contents of '.git' vary as a function of the current
+                ;; status of the Git repo.  Since we want a fixed output, this
+                ;; directory needs to be taken out.
+                (delete-file-recursively ".git")
+                #t)))))
+
+;;; git.scm ends here