python: first fix towards cross-compiling

pkgs/development/interpreters/python/2.6/default.nix

@@ -29,9 +29,10 @@ let
       ./nix-store-mtime.patch
     ];
 
+  nativeBuildInputs = [ bzip2 ];
+
   buildInputs =
-    optional (stdenv ? gcc && stdenv.gcc.libc != null) stdenv.gcc.libc ++
+    optional (stdenv ? gcc && stdenv.gcc.libc != null) stdenv.gcc.libc
-    [ bzip2 ]
     ++ optional zlibSupport zlib;
 
     

pkgs/development/interpreters/python/2.7/default.nix

@@ -33,9 +33,11 @@ let
                                 ${stdenv.gcc.libc}/include/netinet/in.h
   '';
 
+  nativeBuildInputs = [ bzip2 ];
+
   buildInputs =
     optional (stdenv ? gcc && stdenv.gcc.libc != null) stdenv.gcc.libc ++
-    [ bzip2 openssl ]
+    [ openssl ]
     ++ optional zlibSupport zlib;
 
   ensurePurity =

pkgs/development/interpreters/python/3.3/default.nix

@@ -20,7 +20,7 @@ let
   version = "${majorVersion}.1";
 
   buildInputs = filter (p: p != null) [
-    zlib bzip2 gdbm sqlite db4 readline ncurses openssl tcl tk libX11 xproto
+    zlib gdbm sqlite db4 readline ncurses openssl tcl tk libX11 xproto
   ];
 in
 stdenv.mkDerivation {
@@ -45,12 +45,15 @@ stdenv.mkDerivation {
                         )
   '';
 
+  nativeBuildInputs = [ bzip2 ];
+
   setupHook = ./setup-hook.sh;
 
   postInstall = ''
     rm -rf "$out/lib/python${majorVersion}/test"
   '';
 
+
   passthru = {
     zlibSupport = zlib != null;
     sqliteSupport = sqlite != null;