gnu: Add delta.

* gnu/packages/debug.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.

gnu-system.am

@@ -72,6 +72,7 @@ GNU_SYSTEM_MODULES =				\
   gnu/packages/databases.scm			\
   gnu/packages/datamash.scm			\
   gnu/packages/dc.scm				\
+  gnu/packages/debug.scm			\
   gnu/packages/dejagnu.scm			\
   gnu/packages/dictionaries.scm			\
   gnu/packages/disk.scm				\

gnu/packages/debug.scm

@@ -0,0 +1,73 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2014 Eric Bavier <bavier@member.fsf.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 (gnu packages debug)
+  #:use-module (guix packages)
+  #:use-module (guix licenses)
+  #:use-module (guix download)
+  #:use-module (guix build-system gnu)
+  #:use-module (gnu packages perl))
+
+(define-public delta
+  (package
+    (name "delta")
+    (version "2006.08.03")
+    (source
+     (origin
+      (method url-fetch)
+      (uri (list
+            (string-append "http://ftp.de.debian.org/debian/pool/main/d/delta/"
+                           "delta_" version ".orig.tar.gz")
+            ;; This uri seems to send guix download into an infinite loop
+            (string-append "http://delta.tigris.org/files/documents/3103/"
+                           "33566/delta-" version ".tar.gz")))
+      (sha256
+       (base32
+        "184wh35pf2ddx97319s6sgkzpz48xxkbwzcjpycv009bm53lh61q"))))
+    (build-system gnu-build-system)
+    (inputs                             ;Installed programs are perl scripts
+     `(("perl" ,perl)))
+    (arguments
+     `(#:phases
+       (alist-replace
+        'install
+        (lambda* (#:key outputs #:allow-other-keys)
+          ;; Makefile contains no install target
+          (let* ((out (assoc-ref outputs "out"))
+                 (bin (string-append out "/bin"))
+                 (doc (string-append out "/share/doc/delta-" ,version)))
+            (begin
+              (mkdir-p bin)
+              (mkdir-p doc)
+              (for-each (lambda (h)
+                          (copy-file h (string-append doc "/" (basename h))))
+                        `("License.txt" ,@(find-files "www" ".*\\.html")))
+              (for-each (lambda (b)
+                          (copy-file b (string-append bin "/" b)))
+                        `("delta" "multidelta" "topformflat")))))
+        (alist-delete 'configure %standard-phases))))
+    (home-page "http://delta.tigris.org/")
+    (synopsis "Heuristical file minimizer")
+    (description
+     "Delta assists you in minimizing \"interesting\" files subject to a test
+of their interestingness.  A common such situation is when attempting to
+isolate a small failure-inducing substring of a large input that causes your
+program to exhibit a bug.")
+    ;; See License.txt, which is a bsd-3 license, despite the project's
+    ;; home-page pointing to a bsd-2 license.
+    (license bsd-3)))