A case study in transitive overrides. WebKit needs fresh glib. This means it needs a whole slice of system built against glib-2.22.. Added overrides are generic enough, though. So the same way can be used to override everything. I have failed (so far?) to add mkOverridable into stdenv, though.

svn path=/nixpkgs/trunk/; revision=17661

pkgs/development/libraries/avahi/default.nix

@@ -1,6 +1,6 @@
 { fetchurl, stdenv, pkgconfig, libdaemon, dbus, perl, perlXMLParser
 , expat, gettext, intltool, glib, gtk, qt4 ? null, lib
-, qt4Support ? false }:
+, qt4Support ? false, ...}:
 
 assert qt4Support -> qt4 != null;
 

pkgs/development/libraries/consolekit/default.nix

@@ -1,4 +1,5 @@
-{ stdenv, fetchurl, pkgconfig, dbus_glib, zlib, pam, glib, libX11, policykit, expat }:
+{ stdenv, fetchurl, pkgconfig, dbus_glib, zlib, pam, glib, 
+  libX11, policykit, expat, ... }:
 
 stdenv.mkDerivation rec {
   name = "consolekit-0.2.10";

pkgs/development/libraries/gstreamer/default.nix

@@ -1,29 +1,29 @@
 args: with args;
 rec {
-  gstreamer = import ./gstreamer {
+  gstreamer = makeOverridable (import ./gstreamer) {
     inherit (args) fetchurl stdenv perl bison flex
        pkgconfig python which gtkdoc glib libxml2;
   };
 
-  gstPluginsBase = import ./gst-plugins-base {
+  gstPluginsBase = makeOverridable (import ./gst-plugins-base) {
     inherit gstreamer;
     inherit (args) fetchurl stdenv pkgconfig python
       libX11 libXv libXext alsaLib cdparanoia libogg libtheora
       libvorbis freetype pango liboil gtk which gtkdoc;
   };
 
-  gstPluginsGood = import ./gst-plugins-good {
+  gstPluginsGood = makeOverridable (import ./gst-plugins-good) {
     inherit gstPluginsBase;
     inherit (args) fetchurl stdenv pkgconfig aalib cairo flac hal
       libjpeg zlib speex libpng libdv libcaca dbus libiec61883
       libavc1394 ladspaH taglib gdbm pulseaudio libsoup;
   };
 
-  gstFfmpeg = import ./gst-ffmpeg {
+  gstFfmpeg = makeOverridable (import ./gst-ffmpeg) {
     inherit fetchurl stdenv pkgconfig gstPluginsBase bzip2;
   };
 
-  gnonlin = import ./gnonlin {
+  gnonlin = makeOverridable (import ./gnonlin) {
     inherit fetchurl stdenv pkgconfig gstreamer gstPluginsBase;
   };
 }

pkgs/development/libraries/gstreamer/gst-ffmpeg/default.nix

@@ -1,4 +1,4 @@
-{ fetchurl, stdenv, pkgconfig, gstPluginsBase, bzip2 }:
+{ fetchurl, stdenv, pkgconfig, gstPluginsBase, bzip2, ... }:
 
 stdenv.mkDerivation rec {
   name = "gst-ffmpeg-0.10.5";

pkgs/development/libraries/gstreamer/gst-plugins-base/default.nix

@@ -1,7 +1,7 @@
 { fetchurl, stdenv, pkgconfig, python, gstreamer
 , libX11, libXv, libXext, alsaLib, cdparanoia , libogg
 , libtheora, libvorbis, freetype, pango
-, liboil, gtk, which, gtkdoc }:
+, liboil, gtk, which, gtkdoc, ... }:
 
 stdenv.mkDerivation rec {
   name = "gst-plugins-base-0.10.22";

pkgs/development/libraries/gstreamer/gst-plugins-good/default.nix

@@ -1,7 +1,7 @@
 { fetchurl, stdenv, pkgconfig, gstPluginsBase, aalib, cairo
 , flac , hal, libjpeg, zlib, speex, libpng, libdv, libcaca, dbus
 , libiec61883, libavc1394, ladspaH, taglib, gdbm, pulseaudio
-, libsoup
+, libsoup, ...
 }:
 
 stdenv.mkDerivation rec {

pkgs/development/libraries/gstreamer/gstreamer/default.nix

@@ -1,5 +1,5 @@
 { fetchurl, stdenv, perl, bison, flex, pkgconfig, python
-, which, gtkdoc, glib, libxml2 }:
+, which, gtkdoc, glib, libxml2, ... }:
 
 stdenv.mkDerivation rec {
   name = "gstreamer-0.10.22";

pkgs/development/libraries/libjpeg/default.nix

@@ -1,4 +1,4 @@
-{stdenv, fetchurl, libtool, static ? false}: 
+{stdenv, fetchurl, libtool, static ? false, ...}: 
 
 stdenv.mkDerivation {
   name = "libjpeg-6b";

pkgs/development/libraries/liboil/default.nix

@@ -1,4 +1,4 @@
-{stdenv, fetchurl, pkgconfig, glib}:
+{stdenv, fetchurl, pkgconfig, glib, ...}:
 
 stdenv.mkDerivation rec {
   name = "liboil-0.3.15";

pkgs/development/libraries/libxml2/default.nix

@@ -1,4 +1,4 @@
-{stdenv, fetchurl, zlib, python ? null, pythonSupport ? true}:
+{stdenv, fetchurl, zlib, python ? null, pythonSupport ? true, ...}:
 
 assert pythonSupport -> python != null;
 

pkgs/development/libraries/policykit/default.nix

@@ -1,5 +1,5 @@
 { stdenv, fetchurl, pkgconfig, glib, dbus, dbus_glib, expat, pam
-, intltool, gettext, libxslt, docbook_xsl }:
+, intltool, gettext, libxslt, docbook_xsl, ... }:
 
 stdenv.mkDerivation rec {
   name = "policykit-0.9";