diff --git a/pumpkin-data/build/build.rs b/pumpkin-data/build/build.rs
index 799ba62bb..7b0342de0 100644
--- a/pumpkin-data/build/build.rs
+++ b/pumpkin-data/build/build.rs
@@ -48,12 +48,13 @@ mod world_event;
 pub const OUT_DIR: &str = "src/generated";
 
 pub fn main() {
-    let path = Path::new(OUT_DIR);
-    if !path.exists() {
-        let _ = fs::create_dir(OUT_DIR);
+    if let Err(e) = fs::create_dir_all(OUT_DIR) {
+        eprintln!("Failed to create output directory {}: {}", OUT_DIR, e);
     }
-    #[allow(clippy::type_complexity)]
-    let build_functions: Vec<(fn() -> TokenStream, &str)> = vec![
+
+    type BuilderFn = fn() -> TokenStream;
+
+    let build_functions: Vec<(BuilderFn, &str)> = vec![
         (packet::build, "packet.rs"),
         (screen::build, "screen.rs"),
         (particle::build, "particle.rs"),
@@ -97,22 +98,21 @@ pub fn main() {
     ];
 
     build_functions.par_iter().for_each(|(build_fn, file)| {
-        let formatted_code = format_code(&build_fn().to_string());
-
-        write_generated_file(&formatted_code, file);
+        let raw_code = build_fn().to_string();
+        let final_code = format_code(&raw_code);
+        write_generated_file(&final_code.unwrap_or(raw_code), file);
     });
 }
 
 pub fn array_to_tokenstream(array: &[String]) -> TokenStream {
-    let mut variants = TokenStream::new();
-
-    for item in array.iter() {
+    let variants = array.iter().map(|item| {
         let name = format_ident!("{}", item.to_pascal_case());
-        variants.extend([quote! {
-            #name,
-        }]);
+        quote! { #name, }
+    });
+
+    quote! {
+        #(#variants)*
     }
-    variants
 }
 
 pub fn write_generated_file(new_code: &str, out_file: &str) {
@@ -122,39 +122,38 @@ pub fn write_generated_file(new_code: &str, out_file: &str) {
         && let Ok(existing_code) = fs::read_to_string(&path)
         && existing_code == new_code
     {
-        return; // No changes, so we skip writing.
+        return;
     }
 
     fs::write(&path, new_code)
         .unwrap_or_else(|_| panic!("Failed to write to file: {}", path.display()));
 }
 
-pub fn format_code(unformatted_code: &str) -> String {
-    let mut child = Command::new("rustfmt")
+pub struct RustFmtError;
+
+pub fn format_code(unformatted_code: &str) -> Result<String, RustFmtError> {
+    let child_result = Command::new("rustfmt")
         .stdin(Stdio::piped())
         .stdout(Stdio::piped())
-        .stderr(Stdio::piped())
-        .spawn()
-        .expect("Failed to spawn rustfmt process.");
+        .stderr(Stdio::null())
+        .spawn();
 
-    child
-        .stdin
-        .take()
-        .expect("Failed to take rustfmt stdin")
-        .write_all(unformatted_code.as_bytes())
-        .expect("Failed to write to rustfmt stdin.");
+    let mut child = match child_result {
+        Ok(c) => c,
+        Err(_) => return Err(RustFmtError),
+    };
 
-    let output = child
-        .wait_with_output()
-        .expect("Failed to wait for rustfmt process.");
+    // Write the code to rustfmt's stdin
+    if let Some(mut stdin) = child.stdin.take()
+        && stdin.write_all(unformatted_code.as_bytes()).is_err()
+    {
+        return Err(RustFmtError);
+    }
 
-    if output.status.success() {
-        String::from_utf8(output.stdout).expect("rustfmt output was not valid UTF-8.")
-    } else {
-        panic!(
-            "rustfmt failed with status: {}\n--- stderr ---\n{}",
-            output.status,
-            String::from_utf8_lossy(&output.stderr)
-        );
+    match child.wait_with_output() {
+        Ok(output) if output.status.success() => {
+            String::from_utf8(output.stdout).map_err(|_| RustFmtError)
+        }
+        _ => Err(RustFmtError),
     }
 }
diff --git a/pumpkin-protocol/src/serial/mod.rs b/pumpkin-protocol/src/serial/mod.rs
index 7607e65cc..db0d228ca 100644
--- a/pumpkin-protocol/src/serial/mod.rs
+++ b/pumpkin-protocol/src/serial/mod.rs
@@ -6,13 +6,13 @@ use std::io::{Error, Read, Write};
 pub trait PacketWrite {
     fn write<W: Write>(&self, writer: &mut W) -> Result<(), Error>;
     fn write_be<W: Write>(&self, _writer: &mut W) -> Result<(), Error> {
-        panic!("not implemented")
+        todo!()
     }
 }
 
 pub trait PacketRead: Sized {
     fn read<R: Read>(reader: &mut R) -> Result<Self, Error>;
     fn read_be<R: Read>(_reader: &mut R) -> Result<Self, Error> {
-        panic!("not implemented")
+        todo!()
     }
 }
diff --git a/pumpkin/src/command/client_suggestions.rs b/pumpkin/src/command/client_suggestions.rs
index 209295a3f..a3e788dc3 100644
--- a/pumpkin/src/command/client_suggestions.rs
+++ b/pumpkin/src/command/client_suggestions.rs
@@ -54,7 +54,7 @@ pub async fn send_c_commands_packet(player: &Arc<Player>, dispatcher: &CommandDi
 
 #[derive(Debug)]
 struct ProtoNodeBuilder<'a> {
-    child_nodes: Vec<ProtoNodeBuilder<'a>>,
+    child_nodes: Vec<Self>,
     node_type: ProtoNodeType<'a>,
 }
 
diff --git a/pumpkin/src/command/tree/builder.rs b/pumpkin/src/command/tree/builder.rs
index c1095a7c0..35bfc6b51 100644
--- a/pumpkin/src/command/tree/builder.rs
+++ b/pumpkin/src/command/tree/builder.rs
@@ -73,7 +73,7 @@ impl NodeBuilder for LeafNodeBuilder {
 
 pub struct NonLeafNodeBuilder {
     node_type: NodeType,
-    child_nodes: Vec<NonLeafNodeBuilder>,
+    child_nodes: Vec<Self>,
     leaf_nodes: Vec<LeafNodeBuilder>,
 }
 
diff --git a/pumpkin/src/net/bedrock/mod.rs b/pumpkin/src/net/bedrock/mod.rs
index 7edc5b434..ecae087c0 100644
--- a/pumpkin/src/net/bedrock/mod.rs
+++ b/pumpkin/src/net/bedrock/mod.rs
@@ -66,7 +66,7 @@ pub struct BedrockClient {
     pub player: Mutex<Option<Arc<Player>>>,
     /// All Bedrock clients
     /// This list is used to remove the client if the connection gets closed
-    pub be_clients: Arc<Mutex<HashMap<SocketAddr, Arc<BedrockClient>>>>,
+    pub be_clients: Arc<Mutex<HashMap<SocketAddr, Arc<Self>>>>,
 
     tasks: TaskTracker,
     outgoing_packet_queue_send: Sender<Bytes>,
diff --git a/pumpkin/src/plugin/mod.rs b/pumpkin/src/plugin/mod.rs
index baaa7393a..6c63be187 100644
--- a/pumpkin/src/plugin/mod.rs
+++ b/pumpkin/src/plugin/mod.rs
@@ -137,7 +137,7 @@ pub struct PluginManager {
     handlers: Arc<RwLock<HandlerMap>>,
     unloaded_files: RwLock<HashSet<PathBuf>>,
     // Self-reference for sharing with contexts
-    self_ref: RwLock<Option<Arc<PluginManager>>>,
+    self_ref: RwLock<Option<Arc<Self>>>,
     services: Arc<RwLock<HashMap<String, Arc<dyn Payload>>>>,
     // Plugin state tracking
     plugin_states: RwLock<HashMap<String, PluginState>>,
diff --git a/pumpkin/src/world/natural_spawner.rs b/pumpkin/src/world/natural_spawner.rs
index c52750375..c4b2e75d6 100644
--- a/pumpkin/src/world/natural_spawner.rs
+++ b/pumpkin/src/world/natural_spawner.rs
@@ -366,7 +366,7 @@ pub async fn spawn_category_for_position(
         let mut random_group_size = (rng().random::<f32>() * 4.).ceil() as i32;
         let mut inc = 0;
         #[allow(unused_variables)]
-        let mut group_size = 0;
+        let group_size = 0;
         'outer: while inc < random_group_size {
             new_x += rng().random_range(0..6) - rng().random_range(0..6);
             new_z += rng().random_range(0..6) - rng().random_range(0..6);
@@ -419,7 +419,7 @@ pub async fn spawn_category_for_position(
             // TODO isValidPositionForMob(level, mob, f)
             // TODO spawnGroupData = mob.finalizeSpawn(level, level.getCurrentDifficultyAt(mob.blockPosition()), EntitySpawnReason.NATURAL, spawnGroupData);
             spawn_cluster_size += 1;
-            group_size += 1;
+            //group_size += 1;
             world.spawn_entity(entity).await;
             spawn_state.after_spawn(entity_type, &new_pos, world).await;
             if spawn_cluster_size >= entity_type.limit_per_chunk {