I made the whole nixpkgs dependencies available to the cross compiler, no

needing to keep a new tree of expressions apart for the expressions to get
cross-compiled.

I changed the whole way of using cross compilation with nixpkgs, which before
was done through a simple adapter.

Now the adapter became complex, and I've tried to avoid the most obvious
recursivities. For example, the fetchurl expression should
never be cross-compiled, as the gmp, mpfr, and some others, like
some ncurses, perl, ... I made overrided copies of those necessary as
perlNoCross, ncursesNoCross, as stdenvNoCross, keeping in mind that
the stdenv (capable of cross compilation) is built upon stdenvNoCross using
an adapter.

So, to cross compile, instead of building using "nixpkgs/default.nix",
you should build with your
own "myarchiteture.nix", which should have contents like these, for example:

import /etc/nixos/nixpkgs/default.nix
{
    crossSystem = {
        config = "armv5tel-unknown-linux-gnueabi";
        bigEndian = false;
        arch = "arm";
        float = "soft";
    };
}


svn path=/nixpkgs/branches/stdenv-updates/; revision=18398

pkgs/development/libraries/readline/readline6.nix

@@ -8,7 +8,7 @@ stdenv.mkDerivation rec {
     sha256 = "1pn13j6f9376kwki69050x3zh62yb1w31l37rws5nwr5q02xk68i";
   };
 
-  propagatedBuildInputs = [ncurses];
+  propagatedHostInputs = [ncurses];
 
   patchFlags = "-p0";
   patches =