diff --git a/rtchallenge/src/camera.rs b/rtchallenge/src/camera.rs
index 966e56c..1b2cc8f 100644
--- a/rtchallenge/src/camera.rs
+++ b/rtchallenge/src/camera.rs
@@ -243,15 +243,14 @@ impl Camera {
         // Create a worker thread for each CPU core and pin the thread to the core.
         let mut handles = core_ids
             .into_iter()
-            .enumerate()
-            .map(|(i, id)| {
+            .map(|id| {
                 let w = Arc::clone(&world);
                 let c = Arc::clone(&camera);
                 let pixel_req_rx = pixel_req_rx.clone();
                 let pixel_resp_tx = pixel_resp_tx.clone();
                 thread::spawn(move || {
                     core_affinity::set_for_current(id);
-                    render_worker(i, &c, &w, pixel_req_rx, &pixel_resp_tx);
+                    render_worker(&c, &w, pixel_req_rx, &pixel_resp_tx);
                 })
             })
             .collect::<Vec<_>>();
@@ -328,7 +327,6 @@ impl Camera {
 }
 
 fn render_worker(
-    tid: usize,
     c: &Camera,
     w: &World,
     input_chan: Arc<Mutex<Receiver<Request>>>,
@@ -337,8 +335,11 @@ fn render_worker(
     loop {
         let job = { input_chan.lock().unwrap().recv() };
         match job {
-            Err(err) => {
-                eprintln!("Shutting down render_worker {}: {}", tid, err);
+            Err(_) => {
+                // From the docs:
+                // "The recv operation can only fail if the sending half of a
+                // channel (or sync_channel) is disconnected, implying that no
+                // further messages will ever be received."
                 return;
             }
             Ok(req) => match req {