gnu: Add byzanz.

* gnu/packages/gnome.scm (byzanz): New variable.

gnu/packages/gnome.scm

@@ -34,6 +34,7 @@ (define-module (gnu packages gnome)
   #:use-module ((guix licenses) #:prefix license:)
   #:use-module (guix packages)
   #:use-module (guix download)
+  #:use-module (guix git-download)
   #:use-module (guix utils)
   #:use-module (guix build-system gnu)
   #:use-module (guix build-system glib-or-gtk)
@@ -4811,3 +4812,56 @@ (define-public gnome
      "GNOME is an intutive and attractive desktop environment.  It aims to be
 an easy and elegant way to use your computer.")
     (license license:gpl2+)))
+
+(define-public byzanz
+  ;; The last stable release of Byzanz was in 2011, but there have been many
+  ;; useful commits made to the Byzanz repository since then that it would be
+  ;; silly to use such an old release.
+  (let ((commit "f7af3a5bd252db84af8365bd059c117a7aa5c4af"))
+    (package
+      (name "byzanz")
+      (version (string-append "0.2-1." (string-take commit 7)))
+      (source (origin
+                (method git-fetch)
+                (uri (git-reference
+                      (url "git://git.gnome.org/byzanz")
+                      (commit commit)))
+                (sha256
+                 (base32
+                  "1l60myzxf9cav27v5v3nsijlslz9r7ip6d5kiirfpkf9k0w26hz3"))))
+      (build-system glib-or-gtk-build-system)
+      (arguments
+       '(#:phases
+         (modify-phases %standard-phases
+           (add-after 'unpack 'bootstrap
+             (lambda _
+               ;; The build system cleverly detects that we're not building from
+               ;; a release tarball and turns on -Werror for GCC.
+               ;; Unsurprisingly, there is a warning during compilation that
+               ;; causes the build to fail unnecessarily, so we remove the flag.
+               (substitute* '("configure.ac")
+                 (("-Werror") ""))
+               ;; The autogen.sh script in gnome-common will run ./configure
+               ;; by default, which is problematic because source shebangs
+               ;; have not yet been patched.
+               (setenv "NOCONFIGURE" "t")
+               (zero? (system* "sh" "autogen.sh")))))))
+      (native-inputs
+       `(("autoconf" ,autoconf)
+         ("automake" ,automake)
+         ("gnome-common" ,gnome-common)
+         ("intltool" ,intltool)
+         ("libtool" ,libtool)
+         ("pkg-config" ,pkg-config)
+         ("which" ,which)))
+      (inputs
+       `(("glib" ,glib)
+         ("gstreamer" ,gstreamer)
+         ("gst-plugins-base" ,gst-plugins-base)
+         ("gtk+" ,gtk+)))
+      (synopsis "Desktop recording program")
+      (description "Byzanz is a simple desktop recording program with a
+command-line interface.  It can record part or all of an X display for a
+specified duration and save it as a GIF encoded animated image file.")
+      (home-page "https://git.gnome.org/browse/byzanz")
+      (license license:gpl2+))))