Adding a new mkDerivation flag for the cross stdenv, selfNativeBuildInput =

true/false, which tells whether the derivation needs itself as
buildNativeInput.
For example, in order to build cross ncurses, we need the a native build
ncurses.
(As libtool does not work in stdenv, I have not tested this change, to check
whether finally ncurses cross-build)


svn path=/nixpkgs/branches/stdenv-updates/; revision=18489

pkgs/development/libraries/ncurses/default.nix

@@ -12,6 +12,8 @@ stdenv.mkDerivation rec {
     --with-shared --includedir=''${out}/include --without-debug
     ${if unicode then "--enable-widec" else ""}
   '';
+
+  selfNativeBuildInput = true;
     
   preBuild = ''sed -e "s@\([[:space:]]\)sh @\1''${SHELL} @" -i */Makefile Makefile'';
 

pkgs/stdenv/adapters.nix

@@ -111,7 +111,8 @@ rec {
   # builds.
   makeStdenvCross = stdenv: cross: binutilsCross: gccCross: stdenv //
     { mkDerivation = {name ? "", buildInputs ? [], buildNativeInputs ? [],
-            propagatedBuildInputs ? [], propagatedBuildNativeInputs ? [], ...}@args: let
+            propagatedBuildInputs ? [], propagatedBuildNativeInputs ? [],
+            selfNativeBuildInput ? false, ...}@args: let
 
             # *BuildInputs exists temporarily as another name for
             # *HostInputs.
@@ -135,7 +136,8 @@ rec {
                 stdenv.mkDerivation (args // {
                     name = name + "-" + cross.config;
                     buildNativeInputs = buildNativeInputsDrvs
-                      ++ [ gccCross binutilsCross ];
+                      ++ [ gccCross binutilsCross ] ++
+                      stdenv.lib.optional selfNativeBuildInput buildDrv;
                     buildInputs = buildInputsDrvs;
                     propagatedBuildInputs = propagatedBuildInputsDrvs;
                     propagatedBuildNativeInputs = propagatedBuildNativeInputsDrvs;