diff --git a/pkgs/applications/graphics/exrdisplay/default.nix b/pkgs/applications/graphics/exrdisplay/default.nix
index f82f07602f8..6a8b3d6499b 100644
--- a/pkgs/applications/graphics/exrdisplay/default.nix
+++ b/pkgs/applications/graphics/exrdisplay/default.nix
@@ -1,6 +1,6 @@
 args: with args;
 
-assert fltk.flag_set_gl;
+assert fltk.glSupport;
 stdenv.mkDerivation {
 
   name ="openexr_viewers-1.0.1";
diff --git a/pkgs/development/interpreters/python-new/2.5/default.nix b/pkgs/development/interpreters/python-new/2.5/default.nix
index 1bc7ca4b419..588db877602 100644
--- a/pkgs/development/interpreters/python-new/2.5/default.nix
+++ b/pkgs/development/interpreters/python-new/2.5/default.nix
@@ -13,6 +13,7 @@
 p: # p = pkgs
 let 
   inherit (p) lib fetchurl stdenv getConfig;
+  inherit (p.composableDerivation) composableDerivation;
   # withName prevents  nix-env -qa \* from aborting (pythonLibStub is a derivation but hasn't a name)
   withName = lib.mapAttrs (n : v : if (__isAttrs v && (!__hasAttr "name" v)) then null else v);
 in
@@ -24,7 +25,8 @@ in
     # see pythonFull.
     pythonMinimal = ( (import ./python.nix) {
       name = "python-${t.version}";
-      inherit (p) fetchurl stdenv lib bzip2 ncurses composableDerivation;
+      inherit composableDerivation;
+      inherit (p) fetchurl stdenv lib bzip2 ncurses;
       inherit  (p) zlib sqlite db4 readline openssl gdbm;
     });
 
@@ -72,7 +74,7 @@ in
     # lib to verify it works
     # You can define { python25 { debugCmd = "DISPLAY=:0.0 pathtoxterm"; }
     # in your config for easier debugging..
-    pythonLibStub = p.composableDerivation {
+    pythonLibStub = composableDerivation {
       initial = {
           propagatedBuildInputs = [ t.pythonFull ]; # see [1]
           postPhases = ["postAll"]; # using new name so that you dno't override this phase by accident
@@ -465,7 +467,7 @@ in
 
   ### python applications
 
-  pythonExStub = p.composableDerivation {
+  pythonExStub = composableDerivation {
     initial = {
       buildInputs = [p.makeWrapper];
       postPhases = ["wrapExecutables"];
diff --git a/pkgs/lib/default.nix b/pkgs/lib/default.nix
index 6af24f6a6b0..3f7ba67ecf1 100644
--- a/pkgs/lib/default.nix
+++ b/pkgs/lib/default.nix
@@ -803,7 +803,7 @@ rec {
                   else throw "assertion of flag ${a} of derivation ${args.name} failed"
                ) args2.flags );
     in removeAttrs
-      (mergeAttrsByFuncDefaults ([args] ++ opts))
+      (mergeAttrsByFuncDefaults ([args] ++ opts ++ [{ passthru = cfgWithDefaults; }]))
       ["flags" "cfg" "mergeAttrBy" "fixed" ]; # fixed may be passed as fix argument or such
 
 }