Allow passing args to , watch

flake.nix

@@ -83,7 +83,10 @@
           };
 
           watch = {
-            exec = ''cargo watch -x run'';
+            exec = ''
+              set -x
+              cargo watch -x "run -- $*"
+            '';
             description = "Watch for changes and run the project executable";
           };
         };

src/main.rs

@@ -1,3 +1,21 @@
-fn main() {
-    println!("Hello World!");
+use argh::FromArgs;
+
+#[derive(FromArgs)]
+/// Reach new heights.
+struct GoUp {
+    /// whether or not to jump
+    #[argh(switch, short = 'j')]
+    jump: bool,
+
+    /// how high to go
+    #[argh(option)]
+    height: usize,
+
+    /// an optional nickname for the pilot
+    #[argh(option)]
+    pilot_nickname: Option<String>,
+}
+
+fn main() {
+    let up: GoUp = argh::from_env();
 }