Change default from gnome 3.10 to gnome 3.12

nixos/modules/services/x11/desktop-managers/gnome3.nix

···
 
     environment.gnome3.packageSet = mkOption {
       default = pkgs.gnome3;
-      example = literalExample "pkgs.gnome3_12";
+      example = literalExample "pkgs.gnome3_10";
       description = "Which Gnome 3 package set to use.";
     };
     

nixos/tests/gnome3_12.nix nixos/tests/gnome3_10.nix

···
 import ./make-test.nix {
-  name = "gnome3_12";
+  name = "gnome3";
 
   machine =
     { config, pkgs, ... }:
···
       services.xserver.displayManager.auto.enable = true;
       services.xserver.displayManager.auto.user = "alice";
       services.xserver.desktopManager.gnome3.enable = true;
-      environment.gnome3.packageSet = pkgs.gnome3_12;
+      environment.gnome3.packageSet = pkgs.gnome3_10;
     };
 
   testScript =

pkgs/applications/audio/gtkpod/default.nix

···
 { stdenv, fetchurl, pkgconfig, makeWrapper, intltool, libgpod, curl, flac,
-  gnome3_12, gtk3, glib, gettext, perl, perlXMLParser , libglade, flex, libid3tag,
+  gnome, gtk3, glib, gettext, perl, perlXMLParser, flex, libglade, libid3tag,
   libvorbis, hicolor_icon_theme, gdk_pixbuf }:
 
-let
-  gnome = gnome3_12;
-
-in stdenv.mkDerivation rec {
+stdenv.mkDerivation rec {
   version = "2.1.4";
   name = "gtkpod-${version}";
 

pkgs/desktops/gnome-3/3.10/default.nix

···
 
 rec {
   inherit (pkgs) glib gtk2 gtk3 gnome2 upower glib_networking;
+  gnome3 = pkgs.gnome3_10 // { recurseForDerivations = false; };
   gtk = gtk3; # just to be sure
   libcanberra = pkgs.libcanberra_gtk3; # just to be sure
   inherit (pkgs.gnome2) ORBit2;

pkgs/top-level/all-packages.nix

···
   };
 
   gtkpod = callPackage ../applications/audio/gtkpod {
+    gnome = gnome3;
     inherit (gnome) libglade;
   };
 
···
     inherit (pkgs) libsoup libwnck gtk_doc gnome_doc_utils;
   };
 
-  gnome3 = recurseIntoAttrs (callPackage ../desktops/gnome-3/3.10 {
+  gnome3_10 = recurseIntoAttrs (callPackage ../desktops/gnome-3/3.10 {
     callPackage = pkgs.newScope pkgs.gnome3;
     self = pkgs.gnome3;
   });
···
   gnome3_12 = recurseIntoAttrs (callPackage ../desktops/gnome-3/3.12 {
     callPackage = pkgs.newScope pkgs.gnome3_12;
   });
+
+  gnome3 = gnome3_12;
 
   gnome = recurseIntoAttrs gnome2;