Assertions not exists? flake.nix

flake.nix

{
  description = "Description for the project";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

    sops-nix.url = "github:Mic92/sops-nix";
  };

  outputs = inputs@{ flake-parts, ... }:
    flake-parts.lib.mkFlake { inherit inputs; } {
      imports = (with inputs; [
        sops-nix.nixosModules.sops
      ]);
      systems = [ "x86_64-linux" "aarch64-darwin" "x86_64-darwin" ];
      perSystem = { config, self', inputs', pkgs, system, ... }: { };
    };
}