gtk3 stack: go back to gnome-3.12 branches for now

pkgs/development/libraries/at-spi2-atk/default.nix

@@ -2,14 +2,14 @@
 , intltool, dbus_glib, at_spi2_core, libSM }:
 
 stdenv.mkDerivation rec {
-  versionMajor = "2.14";
+  versionMajor = "2.12";
   versionMinor = "1";
   moduleName   = "at-spi2-atk";
   name = "${moduleName}-${versionMajor}.${versionMinor}";
 
   src = fetchurl {
     url = "mirror://gnome/sources/${moduleName}/${versionMajor}/${name}.tar.xz";
-    sha256 = "1jvvs5bb63xa8ip4cvmpmyyc35gyh39bvwn967wabw7dc3m393q5";
+    sha256 = "5fa9c527bdec028e06797563cd52d49bcf06f638549df983424d88db89bb1336";
   };
 
   buildInputs = [ python pkgconfig popt atk libX11 libICE xlibs.libXtst libXi

pkgs/development/libraries/at-spi2-core/default.nix

@@ -2,14 +2,14 @@
 , libX11, xextproto, libSM, libICE, libXtst, libXi, gobjectIntrospection }:
 
 stdenv.mkDerivation rec {
-  versionMajor = "2.14";
+  versionMajor = "2.12";
   versionMinor = "0";
   moduleName   = "at-spi2-core";
   name = "${moduleName}-${versionMajor}.${versionMinor}";
 
   src = fetchurl {
     url = "mirror://gnome/sources/${moduleName}/${versionMajor}/${name}.tar.xz";
-    sha256 = "1j0l4l4qx0i4s9zzwhiwvw3hfjnrbmknvwkzvqpvb5gndqpb01sq";
+    sha256 = "12gvsgdaxnxskndlhlmdkc50cfqgmzfc4n8la9944fz5k3fhwmfv";
   };
 
   buildInputs = [

pkgs/development/libraries/atk/default.nix

@@ -1,7 +1,7 @@
 { stdenv, fetchurl, pkgconfig, perl, glib, libintlOrEmpty, gobjectIntrospection }:
 
 let
-  ver_maj = "2.14";
+  ver_maj = "2.12";
   ver_min = "0";
 in
 stdenv.mkDerivation rec {
@@ -9,7 +9,7 @@ stdenv.mkDerivation rec {
 
   src = fetchurl {
     url = "mirror://gnome/sources/atk/${ver_maj}/${name}.tar.xz";
-    sha256 = "1bgvp0isbmf0vb282pncsachqgkrg5zk6an2cv077cdz685wqx98";
+    sha256 = "13zijfcmx7sda83qkryzsmr9hw0r3b73xkagq9cmm733fhcl7a28";
   };
 
   buildInputs = libintlOrEmpty;

pkgs/development/libraries/gobject-introspection/default.nix

@@ -5,7 +5,7 @@
 # In that case its about 6MB which could be separated
 
 let
-  ver_maj = "1.42";
+  ver_maj = "1.40";
   ver_min = "0";
 in
 stdenv.mkDerivation rec {
@@ -13,7 +13,7 @@ stdenv.mkDerivation rec {
 
   src = fetchurl {
     url = "mirror://gnome/sources/gobject-introspection/${ver_maj}/${name}.tar.xz";
-    sha256 = "1xwm7wmr9r9wp6xljb3bckx3a4siybavaq39w46ly7gpskxfv8iv";
+    sha256 = "162flbzwzz0b8axab2gimc4dglpaw88fh1d177zfg0whczlpbsln";
   };
 
   buildInputs = [ flex bison glib pkgconfig python ]