{
  inputs = {
    nixpkgs.url      = "github:nixos/nixpkgs";
    flake-utils.url  = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils, ... }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs { inherit system; };
      in with pkgs; {
        devShell = mkShell {
          buildInputs = [
            psmisc
            watchexec
          ];
        };
      }
    );
}