flake.nix failing

flake.nix

{
  description = "A PHP development environment";

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

  outputs = { self, flake-utils, nixpkgs }:
    flake-utils.lib.eachDefaultSystem
      (system:
        let
          pkgs = import nixpkgs {
            inherit system;
            config = {
              allowUnfree = true;
            };
          };

        in
        {
          packages = {
			default = pkgs.mkShellNoCC {
				name = "devShellPHP";
				buildInputs = [
					(pkgs.php.buildEnv {
						extensions = ({ enabled, all }: enabled ++ (with all; [
							oci8
						]));
					})
				];
			};
		  };
		}
      );
}