{
  outputs =
    { self, nixpkgs }:
    let
      shell =
        { pkgs }:
        pkgs.mkShell {
          packages = with pkgs; [
            ncurses
            dialog
            perl
            bashInteractive
            flex
            bison
            buildPackages.qemu
          ];
          shellHook = ''
            # Do not attempt cross compilation.
            export CROSS_COMPILE=
            # These are set by the compiler’s shellHook but mk refuses to work when these are set.
            unset CC CPP CXX AR AS LD
          '';
        };

      lib = import "${nixpkgs}/lib";
      forAll = list: f: lib.genAttrs list f;
    in
    {
      devShells = forAll [ "x86_64-linux" ] (system: {
        default = shell {
          pkgs = nixpkgs.legacyPackages.${system};
        };
      });
    };
}