{
  description = "Exercism PHP Track";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
  };

  outputs = { self, nixpkgs }:
  let
    systems = [
      "x86_64-linux"
      "aarch64-linux"
      "aarch64-darwin"
    ];

    forAllSystems = f:
      nixpkgs.lib.genAttrs systems (system:
        f (import nixpkgs { inherit system; })
      );
  in
  {
    devShells = forAllSystems (pkgs: {
      default = pkgs.mkShell {
        packages = with pkgs; [
          exercism
          php85
          phpunit
        ];
      };
    });
  };
}