working version

default.nix

@@ -0,0 +1,22 @@
+# default.nix — local test entry-point
+#
+# Usage
+# -----
+#   nix-build                 # build the package
+#   nix-build -A fladder      # explicit attribute (same result)
+#   ./result/bin/fladder      # run the built binary
+#
+# To drop into a shell with the package available:
+#   nix-shell -p "$(nix-build --no-out-link)"
+#
+# Or with nix shell (flake-agnostic):
+#   nix shell "$(nix-build --no-out-link)"
+
+let
+  # Pin to a recent nixpkgs revision that ships NixOS 25.11 packages.
+  # Replace <nixpkgs> with a pinned fetchTarball for fully reproducible builds.
+  pkgs = import <nixpkgs> { };
+in
+{
+  fladder = pkgs.callPackage ./package.nix { };
+}