{ pkgs ? import <nixpkgs> {} }:
  pkgs.mkShell {
    # nativeBuildInputs is usually what you want -- tools you need to run
    nativeBuildInputs =
      let erlpkgs = pkgs.buildPackages.beam.packages.erlangR25;
      in [
        erlpkgs.elixir
        erlpkgs.hex
      ];

    buildInputs = [
      pkgs.libsodium
    ];
  }