fix: unbound var

flake.nix

@@ -13,14 +13,13 @@ outputs = { self, nixpkgs, flake-utils}:
     in {
       packages.default = pkgs.writeShellApplication {
         name = "ngcp";
-        text = ./ngcp.sh;
+        text = builtins.readFile ./ngcp.sh;
         runtimeInputs = with pkgs; [
           git
           libnotify
           jq
         ];
       };
-      mainProgram = "ngpcp";
       apps.default = {
         type = "app";
         program = "${self.packages.${system}.default}/bin/ngcp";

ngcp.sh

@@ -1,6 +1,11 @@
 set -euo pipefail
 trap 'echo "Interrupted or failed. Repo may be mid-rebase/cherry-pick." ; exit 1' INT ERR
 
+if [[ $# -eq 0 ]]; then
+  echo "Usage: ngcp [mode] [options]"
+  echo "Run 'ngcp --help' for more information."
+  exit 1
+fi
 
 # waits for an internet connection. It pings both Google DNS  and Cloudfare dns in case one of them is down
 pings=0