gnu: Add taskwarrior.

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

gnu-system.am

@@ -280,6 +280,7 @@ GNU_SYSTEM_MODULES =				\
   gnu/packages/swig.scm				\
   gnu/packages/sxiv.scm				\
   gnu/packages/synergy.scm			\
+  gnu/packages/task-management.scm		\
   gnu/packages/tbb.scm				\
   gnu/packages/tcl.scm				\
   gnu/packages/tcsh.scm				\

gnu/packages/task-management.scm

@@ -0,0 +1,61 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2015 Tomáš Čech <sleep_walker@suse.cz>
+;;;
+;;; 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 task-management)
+  #:use-module ((guix licenses) #:prefix license:)
+  #:use-module (guix packages)
+  #:use-module (gnu packages gnutls)
+  #:use-module (gnu packages linux)
+  #:use-module (gnu packages lua)
+  #:use-module (guix download)
+  #:use-module (guix build-system cmake))
+
+(define-public taskwarrior
+  (package
+    (name "taskwarrior")
+    (version "2.4.3")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (string-append
+             "http://taskwarrior.org/download/task-" version ".tar.gz"))
+       (sha256 (base32
+                "1lkbw2fhshynbl7hppar1viapyrs712s14xhd8p3l8gyhvxbh0mv"))))
+    (build-system cmake-build-system)
+    (inputs
+     `(("gnutls" ,gnutls)
+       ("lua" ,lua)
+       ("util-linux" ,util-linux)))
+    (arguments
+     `(#:tests? #f ; No tests implemented.
+       #:phases
+       (modify-phases %standard-phases
+         (add-before
+          'patch-source-shebangs 'remove-broken-symlinks
+          (lambda _
+            ;; These files are broken symlinks - delete them.
+            (delete-file "src/cal")
+            (delete-file "src/calendar")
+            (delete-file "src/tw"))))))
+     (home-page "http://taskwarrior.org")
+    (synopsis "Command line task manager")
+    (description
+     "Taskwarrior is a command-line task manager following the Getting Things
+Done time management method.  It supports network synchronization, filtering
+and querying data, exposing task data in multiple formats to other tools.")
+    (license license:expat)))