Can't compile dwm: X11/Xlib.h not found

Great news: I learned (at a VERY basic level) how to use nix-shell! The idea of encapsulated development environments is so great! That’s what I’ve been using with python-virtual environments for a few years now. Having that for EVERY development environment is just crazy clean, from a system-state point of view. Here’s my current shell.nix:

{ pkgs ? import <nixpkgs> {} }:
  pkgs.mkShell {
    nativeBuildInputs = with pkgs; [
      gnumake
      xorg.libX11.dev
      xorg.libXft
      xorg.libXinerama
    ];
}

Do you think there’s something to be improved there?