diff --git a/Cargo.lock b/Cargo.lock
index f2d0dcce3..f4e171c69 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -305,7 +305,6 @@ dependencies = [
  "slog-term",
  "store",
  "tokio 0.2.21",
- "toml",
  "types",
  "version",
 ]
diff --git a/Makefile b/Makefile
index 7f8ea3052..76da24603 100644
--- a/Makefile
+++ b/Makefile
@@ -51,9 +51,9 @@ test: test-release
 test-full: cargo-fmt test-release test-debug test-ef
 
 # Lints the code for bad style and potentially unsafe arithmetic using Clippy.
-# Clippy lints are opt-in per-crate for now, which is why we allow all by default.
+# Clippy lints are opt-in per-crate for now. By default, everything is allowed except for performance and correctness lints.
 lint:
-	cargo clippy --all -- -A clippy::all
+	cargo clippy --all -- -A clippy::all --D clippy::perf --D clippy::correctness
 
 # Runs the makefile in the `ef_tests` repo.
 #
diff --git a/beacon_node/Cargo.toml b/beacon_node/Cargo.toml
index 4d70b84f3..ca5ad0553 100644
--- a/beacon_node/Cargo.toml
+++ b/beacon_node/Cargo.toml
@@ -37,6 +37,5 @@ genesis = { path = "genesis" }
 eth2_testnet_config = { path = "../common/eth2_testnet_config" }
 eth2_libp2p = { path = "./eth2_libp2p" }
 eth2_ssz = "0.1.2"
-toml = "0.5.6"
 serde = "1.0.110"
 clap_utils = { path = "../common/clap_utils" }
diff --git a/beacon_node/beacon_chain/src/beacon_chain.rs b/beacon_node/beacon_chain/src/beacon_chain.rs
index b00aea6f0..143f07e0d 100644
--- a/beacon_node/beacon_chain/src/beacon_chain.rs
+++ b/beacon_node/beacon_chain/src/beacon_chain.rs
@@ -1229,14 +1229,9 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             }
         }
 
-        while !filtered_chain_segment.is_empty() {
+        while let Some((_root, block)) = filtered_chain_segment.first() {
             // Determine the epoch of the first block in the remaining segment.
-            let start_epoch = filtered_chain_segment
-                .first()
-                .map(|(_root, block)| block)
-                .expect("chain_segment cannot be empty")
-                .slot()
-                .epoch(T::EthSpec::slots_per_epoch());
+            let start_epoch = block.slot().epoch(T::EthSpec::slots_per_epoch());
 
             // The `last_index` indicates the position of the last block that is in the current
             // epoch of `start_epoch`.
diff --git a/beacon_node/beacon_chain/src/observed_attesters.rs b/beacon_node/beacon_chain/src/observed_attesters.rs
index bc428fd5d..8cc3f5070 100644
--- a/beacon_node/beacon_chain/src/observed_attesters.rs
+++ b/beacon_node/beacon_chain/src/observed_attesters.rs
@@ -197,7 +197,7 @@ impl<T: Item, E: EthSpec> AutoPruningContainer<T, E> {
                 .map(|(_epoch, item)| item.len())
                 .fold((0, 0), |(count, sum), len| (count + 1, sum + len));
 
-            let initial_capacity = sum.checked_div(count).unwrap_or(T::default_capacity());
+            let initial_capacity = sum.checked_div(count).unwrap_or_else(T::default_capacity);
 
             let mut item = T::with_capacity(initial_capacity);
             item.insert(validator_index);
diff --git a/beacon_node/beacon_chain/src/test_utils.rs b/beacon_node/beacon_chain/src/test_utils.rs
index e98c21051..aaf2d6e96 100644
--- a/beacon_node/beacon_chain/src/test_utils.rs
+++ b/beacon_node/beacon_chain/src/test_utils.rs
@@ -504,7 +504,7 @@ where
         };
 
         let sk = &self.keypairs[proposer_index].sk;
-        let fork = &state.fork.clone();
+        let fork = &state.fork;
 
         let randao_reveal = {
             let epoch = slot.epoch(E::slots_per_epoch());
@@ -676,7 +676,7 @@ where
                             selection_proof.is_aggregator(bc.committee.len(), spec).unwrap_or(false)
                         })
                         .copied()
-                        .expect(&format!(
+                        .unwrap_or_else(|| panic!(
                             "Committee {} at slot {} with {} attesting validators does not have any aggregators",
                             bc.index, state.slot, bc.committee.len()
                         ));
diff --git a/beacon_node/eth2_libp2p/src/behaviour/handler/delegate.rs b/beacon_node/eth2_libp2p/src/behaviour/handler/delegate.rs
index b20fe5170..2863efd85 100644
--- a/beacon_node/eth2_libp2p/src/behaviour/handler/delegate.rs
+++ b/beacon_node/eth2_libp2p/src/behaviour/handler/delegate.rs
@@ -70,7 +70,7 @@ pub enum DelegateIn<TSpec: EthSpec> {
 pub enum DelegateOut<TSpec: EthSpec> {
     Gossipsub(<GossipHandler as ProtocolsHandler>::OutEvent),
     RPC(<RPCHandler<TSpec> as ProtocolsHandler>::OutEvent),
-    Identify(<IdentifyHandler as ProtocolsHandler>::OutEvent),
+    Identify(Box<<IdentifyHandler as ProtocolsHandler>::OutEvent>),
 }
 
 /// Wrapper around the `ProtocolsHandler::Error` types of the handlers.
@@ -342,7 +342,9 @@ impl<TSpec: EthSpec> ProtocolsHandler for DelegatingHandler<TSpec> {
 
         match self.identify_handler.poll(cx) {
             Poll::Ready(ProtocolsHandlerEvent::Custom(event)) => {
-                return Poll::Ready(ProtocolsHandlerEvent::Custom(DelegateOut::Identify(event)));
+                return Poll::Ready(ProtocolsHandlerEvent::Custom(DelegateOut::Identify(
+                    Box::new(event),
+                )));
             }
             Poll::Ready(ProtocolsHandlerEvent::Close(event)) => {
                 return Poll::Ready(ProtocolsHandlerEvent::Close(DelegateError::Identify(event)));
diff --git a/beacon_node/eth2_libp2p/src/behaviour/handler/mod.rs b/beacon_node/eth2_libp2p/src/behaviour/handler/mod.rs
index 64d0bcaca..f87ba6dbe 100644
--- a/beacon_node/eth2_libp2p/src/behaviour/handler/mod.rs
+++ b/beacon_node/eth2_libp2p/src/behaviour/handler/mod.rs
@@ -42,7 +42,7 @@ pub enum BehaviourHandlerIn<TSpec: EthSpec> {
 }
 
 pub enum BehaviourHandlerOut<TSpec: EthSpec> {
-    Delegate(DelegateOut<TSpec>),
+    Delegate(Box<DelegateOut<TSpec>>),
     // TODO: replace custom with events to send
     Custom,
 }
@@ -119,7 +119,7 @@ impl<TSpec: EthSpec> ProtocolsHandler for BehaviourHandler<TSpec> {
         match self.delegate.poll(cx) {
             Poll::Ready(ProtocolsHandlerEvent::Custom(event)) => {
                 return Poll::Ready(ProtocolsHandlerEvent::Custom(
-                    BehaviourHandlerOut::Delegate(event),
+                    BehaviourHandlerOut::Delegate(Box::new(event)),
                 ))
             }
             Poll::Ready(ProtocolsHandlerEvent::Close(err)) => {
diff --git a/beacon_node/eth2_libp2p/src/behaviour/mod.rs b/beacon_node/eth2_libp2p/src/behaviour/mod.rs
index 1aca8a5dd..cd54c7f6d 100644
--- a/beacon_node/eth2_libp2p/src/behaviour/mod.rs
+++ b/beacon_node/eth2_libp2p/src/behaviour/mod.rs
@@ -160,10 +160,10 @@ impl<TSpec: EthSpec> NetworkBehaviour for Behaviour<TSpec> {
     ) {
         match event {
             // Events comming from the handler, redirected to each behaviour
-            BehaviourHandlerOut::Delegate(delegate) => match delegate {
+            BehaviourHandlerOut::Delegate(delegate) => match *delegate {
                 DelegateOut::Gossipsub(ev) => self.gossipsub.inject_event(peer_id, conn_id, ev),
                 DelegateOut::RPC(ev) => self.eth2_rpc.inject_event(peer_id, conn_id, ev),
-                DelegateOut::Identify(ev) => self.identify.inject_event(peer_id, conn_id, ev),
+                DelegateOut::Identify(ev) => self.identify.inject_event(peer_id, conn_id, *ev),
             },
             /* Custom events sent BY the handler */
             BehaviourHandlerOut::Custom => {
diff --git a/beacon_node/eth2_libp2p/src/config.rs b/beacon_node/eth2_libp2p/src/config.rs
index 6facb7750..a9af3eea6 100644
--- a/beacon_node/eth2_libp2p/src/config.rs
+++ b/beacon_node/eth2_libp2p/src/config.rs
@@ -56,6 +56,9 @@ pub struct Config {
     /// Client version
     pub client_version: String,
 
+    /// Disables the discovery protocol from starting.
+    pub disable_discovery: bool,
+
     /// List of extra topics to initially subscribe to as strings.
     pub topics: Vec<GossipKind>,
 }
@@ -104,7 +107,7 @@ impl Default for Config {
             .request_retries(2)
             .enr_peer_update_min(2) // prevents NAT's should be raised for mainnet
             .query_parallelism(5)
-            .query_timeout(Duration::from_secs(60))
+            .query_timeout(Duration::from_secs(30))
             .query_peer_timeout(Duration::from_secs(2))
             .ip_limit() // limits /24 IP's in buckets.
             .ping_interval(Duration::from_secs(300))
@@ -125,6 +128,7 @@ impl Default for Config {
             boot_nodes: vec![],
             libp2p_nodes: vec![],
             client_version: version::version(),
+            disable_discovery: false,
             topics,
         }
     }
diff --git a/beacon_node/eth2_libp2p/src/discovery/mod.rs b/beacon_node/eth2_libp2p/src/discovery/mod.rs
index ca6cd9fe8..aae58d15d 100644
--- a/beacon_node/eth2_libp2p/src/discovery/mod.rs
+++ b/beacon_node/eth2_libp2p/src/discovery/mod.rs
@@ -51,7 +51,7 @@ const FIND_NODE_QUERY_CLOSEST_PEERS: usize = 16;
 pub enum DiscoveryEvent {
     /// A query has completed. The first parameter is the `min_ttl` of the peers if it is specified
     /// and the second parameter are the discovered peers.
-    QueryResult(Option<Instant>, Box<Vec<Enr>>),
+    QueryResult(Option<Instant>, Vec<Enr>),
     /// This indicates that our local UDP socketaddr has been updated and we should inform libp2p.
     SocketUpdated(SocketAddr),
 }
@@ -112,10 +112,12 @@ enum EventStream {
     ),
     /// The future has completed.
     Present(mpsc::Receiver<Discv5Event>),
-    // The future has failed, there are no events from discv5.
-    Failed,
+    // The future has failed or discv5 has been disabled. There are no events from discv5.
+    InActive,
 }
 
+/// The main discovery service. This can be disabled via CLI arguements. When disabled the
+/// underlying processes are not started, but this struct still maintains our current ENR.
 pub struct Discovery<TSpec: EthSpec> {
     /// A collection of seen live ENRs for quick lookup and to map peer-id's to ENRs.
     cached_enrs: LruCache<PeerId, Enr>,
@@ -145,6 +147,10 @@ pub struct Discovery<TSpec: EthSpec> {
     /// The discv5 event stream.
     event_stream: EventStream,
 
+    /// Indicates if the discovery service has been started. When the service is disabled, this is
+    /// always false.
+    started: bool,
+
     /// Logger for the discovery behaviour.
     log: slog::Logger,
 }
@@ -196,12 +202,16 @@ impl<TSpec: EthSpec> Discovery<TSpec> {
             });
         }
 
-        // Start the discv5 service.
-        discv5.start(listen_socket);
-        debug!(log, "Discovery service started");
+        // Start the discv5 service and obtain an event stream
+        let event_stream = if !config.disable_discovery {
+            discv5.start(listen_socket);
+            debug!(log, "Discovery service started");
+            EventStream::Awaiting(Box::pin(discv5.event_stream()))
+        } else {
+            EventStream::InActive
+        };
 
         // Obtain the event stream
-        let event_stream = EventStream::Awaiting(Box::pin(discv5.event_stream()));
 
         Ok(Self {
             cached_enrs: LruCache::new(50),
@@ -211,6 +221,7 @@ impl<TSpec: EthSpec> Discovery<TSpec> {
             active_queries: FuturesUnordered::new(),
             discv5,
             event_stream,
+            started: !config.disable_discovery,
             log,
             enr_dir,
         })
@@ -223,10 +234,11 @@ impl<TSpec: EthSpec> Discovery<TSpec> {
 
     /// This adds a new `FindPeers` query to the queue if one doesn't already exist.
     pub fn discover_peers(&mut self) {
-        // If we are in the process of a query, don't bother queuing a new one.
-        if self.find_peer_active {
+        // If the discv5 service isn't running or we are in the process of a query, don't bother queuing a new one.
+        if !self.started || self.find_peer_active {
             return;
         }
+
         // If there is not already a find peer's query queued, add one
         let query = QueryType::FindPeers;
         if !self.queued_queries.contains(&query) {
@@ -239,54 +251,11 @@ impl<TSpec: EthSpec> Discovery<TSpec> {
 
     /// Processes a request to search for more peers on a subnet.
     pub fn discover_subnet_peers(&mut self, subnet_id: SubnetId, min_ttl: Option<Instant>) {
-        self.add_subnet_query(subnet_id, min_ttl, 0);
-    }
-
-    /// Adds a subnet query if one doesn't exist. If a subnet query already exists, this
-    /// updates the min_ttl field.
-    fn add_subnet_query(&mut self, subnet_id: SubnetId, min_ttl: Option<Instant>, retries: usize) {
-        // remove the entry and complete the query if greater than the maximum search count
-        if retries >= MAX_DISCOVERY_RETRY {
-            debug!(
-                self.log,
-                "Subnet peer discovery did not find sufficient peers. Reached max retry limit"
-            );
+        // If the discv5 service isn't running, ignore queries
+        if !self.started {
             return;
         }
-
-        // Search through any queued requests and update the timeout if a query for this subnet
-        // already exists
-        let mut found = false;
-        for query in self.queued_queries.iter_mut() {
-            if let QueryType::Subnet {
-                subnet_id: ref mut q_subnet_id,
-                min_ttl: ref mut q_min_ttl,
-                retries: ref mut q_retries,
-            } = query
-            {
-                if *q_subnet_id == subnet_id {
-                    if *q_min_ttl < min_ttl {
-                        *q_min_ttl = min_ttl;
-                    }
-                    // update the number of retries
-                    *q_retries = retries;
-                    // mimic an `Iter::Find()` and short-circuit the loop
-                    found = true;
-                    break;
-                }
-            }
-        }
-        if !found {
-            // Set up the query and add it to the queue
-            let query = QueryType::Subnet {
-                subnet_id,
-                min_ttl,
-                retries,
-            };
-            // update the metrics and insert into the queue.
-            metrics::set_gauge(&metrics::DISCOVERY_QUEUE, self.queued_queries.len() as i64);
-            self.queued_queries.push_back(query);
-        }
+        self.add_subnet_query(subnet_id, min_ttl, 0);
     }
 
     /// Add an ENR to the routing table of the discovery mechanism.
@@ -295,7 +264,7 @@ impl<TSpec: EthSpec> Discovery<TSpec> {
         self.cached_enrs.put(enr.peer_id(), enr.clone());
 
         if let Err(e) = self.discv5.add_enr(enr) {
-            warn!(
+            debug!(
                 self.log,
                 "Could not add peer to the local routing table";
                 "error" => format!("{}", e)
@@ -359,7 +328,7 @@ impl<TSpec: EthSpec> Discovery<TSpec> {
             .enr_insert(BITFIELD_ENR_KEY, current_bitfield.as_ssz_bytes());
 
         // replace the global version
-        *self.network_globals.local_enr.write() = self.discv5.local_enr().clone();
+        *self.network_globals.local_enr.write() = self.discv5.local_enr();
         Ok(())
     }
 
@@ -391,11 +360,58 @@ impl<TSpec: EthSpec> Discovery<TSpec> {
             });
 
         // replace the global version with discovery version
-        *self.network_globals.local_enr.write() = self.discv5.local_enr().clone();
+        *self.network_globals.local_enr.write() = self.discv5.local_enr();
     }
 
     /* Internal Functions */
 
+    /// Adds a subnet query if one doesn't exist. If a subnet query already exists, this
+    /// updates the min_ttl field.
+    fn add_subnet_query(&mut self, subnet_id: SubnetId, min_ttl: Option<Instant>, retries: usize) {
+        // remove the entry and complete the query if greater than the maximum search count
+        if retries >= MAX_DISCOVERY_RETRY {
+            debug!(
+                self.log,
+                "Subnet peer discovery did not find sufficient peers. Reached max retry limit"
+            );
+            return;
+        }
+
+        // Search through any queued requests and update the timeout if a query for this subnet
+        // already exists
+        let mut found = false;
+        for query in self.queued_queries.iter_mut() {
+            if let QueryType::Subnet {
+                subnet_id: ref mut q_subnet_id,
+                min_ttl: ref mut q_min_ttl,
+                retries: ref mut q_retries,
+            } = query
+            {
+                if *q_subnet_id == subnet_id {
+                    if *q_min_ttl < min_ttl {
+                        *q_min_ttl = min_ttl;
+                    }
+                    // update the number of retries
+                    *q_retries = retries;
+                    // mimic an `Iter::Find()` and short-circuit the loop
+                    found = true;
+                    break;
+                }
+            }
+        }
+        if !found {
+            // Set up the query and add it to the queue
+            let query = QueryType::Subnet {
+                subnet_id,
+                min_ttl,
+                retries,
+            };
+            // update the metrics and insert into the queue.
+            metrics::set_gauge(&metrics::DISCOVERY_QUEUE, self.queued_queries.len() as i64);
+            self.queued_queries.push_back(query);
+        }
+    }
+
     /// Consume the discovery queue and initiate queries when applicable.
     ///
     /// This also sanitizes the queue removing out-dated queries.
@@ -572,6 +588,10 @@ impl<TSpec: EthSpec> Discovery<TSpec> {
 
     // Main execution loop to be driven by the peer manager.
     pub fn poll(&mut self, cx: &mut Context) -> Poll<DiscoveryEvent> {
+        if !self.started {
+            return Poll::Pending;
+        }
+
         // Process the query queue
         self.process_queue();
 
@@ -582,7 +602,7 @@ impl<TSpec: EthSpec> Discovery<TSpec> {
                 self.cached_enrs.put(enr.peer_id(), enr);
             }
             // return the result to the peer manager
-            return Poll::Ready(DiscoveryEvent::QueryResult(min_ttl, Box::new(result)));
+            return Poll::Ready(DiscoveryEvent::QueryResult(min_ttl, result));
         }
 
         // Process the server event stream
@@ -594,12 +614,12 @@ impl<TSpec: EthSpec> Discovery<TSpec> {
                         Ok(stream) => self.event_stream = EventStream::Present(stream),
                         Err(e) => {
                             slog::crit!(self.log, "Discv5 event stream failed"; "error" => e.to_string());
-                            self.event_stream = EventStream::Failed;
+                            self.event_stream = EventStream::InActive;
                         }
                     }
                 }
             }
-            EventStream::Failed => {} // ignore checking the stream
+            EventStream::InActive => {} // ignore checking the stream
             EventStream::Present(ref mut stream) => {
                 while let Ok(event) = stream.try_recv() {
                     match event {
diff --git a/beacon_node/eth2_libp2p/src/peer_manager/mod.rs b/beacon_node/eth2_libp2p/src/peer_manager/mod.rs
index 5d8720289..c384bfb31 100644
--- a/beacon_node/eth2_libp2p/src/peer_manager/mod.rs
+++ b/beacon_node/eth2_libp2p/src/peer_manager/mod.rs
@@ -422,7 +422,7 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
     /// with a new `PeerId` which involves a discovery routing table lookup. We could dial the
     /// multiaddr here, however this could relate to duplicate PeerId's etc. If the lookup
     /// proves resource constraining, we should switch to multiaddr dialling here.
-    fn peers_discovered(&mut self, peers: Vec<Enr>, min_ttl: Option<Instant>) {
+    fn peers_discovered(&mut self, peers: &[Enr], min_ttl: Option<Instant>) {
         for enr in peers {
             let peer_id = enr.peer_id();
 
@@ -623,7 +623,7 @@ impl<TSpec: EthSpec> Stream for PeerManager<TSpec> {
             match event {
                 DiscoveryEvent::SocketUpdated(socket_addr) => self.socket_updated(socket_addr),
                 DiscoveryEvent::QueryResult(min_ttl, peers) => {
-                    self.peers_discovered(*peers, min_ttl)
+                    self.peers_discovered(&peers, min_ttl)
                 }
             }
         }
diff --git a/beacon_node/eth2_libp2p/src/rpc/handler.rs b/beacon_node/eth2_libp2p/src/rpc/handler.rs
index 1a1292faa..29bc3504c 100644
--- a/beacon_node/eth2_libp2p/src/rpc/handler.rs
+++ b/beacon_node/eth2_libp2p/src/rpc/handler.rs
@@ -169,7 +169,7 @@ where
     /// A response has been sent, pending writing.
     ResponsePendingSend {
         /// The substream used to send the response
-        substream: InboundFramed<NegotiatedSubstream, TSpec>,
+        substream: Box<InboundFramed<NegotiatedSubstream, TSpec>>,
         /// The message that is attempting to be sent.
         message: RPCCodedResponse<TSpec>,
         /// Whether a stream termination is requested. If true the stream will be closed after
@@ -180,7 +180,7 @@ where
     /// A response has been sent, pending flush.
     ResponsePendingFlush {
         /// The substream used to send the response
-        substream: InboundFramed<NegotiatedSubstream, TSpec>,
+        substream: Box<InboundFramed<NegotiatedSubstream, TSpec>>,
         /// Whether a stream termination is requested. If true the stream will be closed after
         /// this send. Otherwise it will transition to an idle state until a stream termination is
         /// requested or a timeout is reached.
@@ -188,9 +188,9 @@ where
     },
     /// The response stream is idle and awaiting input from the application to send more chunked
     /// responses.
-    ResponseIdle(InboundFramed<NegotiatedSubstream, TSpec>),
+    ResponseIdle(Box<InboundFramed<NegotiatedSubstream, TSpec>>),
     /// The substream is attempting to shutdown.
-    Closing(InboundFramed<NegotiatedSubstream, TSpec>),
+    Closing(Box<InboundFramed<NegotiatedSubstream, TSpec>>),
     /// Temporary state during processing
     Poisoned,
 }
@@ -201,12 +201,12 @@ pub enum OutboundSubstreamState<TSpec: EthSpec> {
     /// handler because GOODBYE requests can be handled and responses dropped instantly.
     RequestPendingResponse {
         /// The framed negotiated substream.
-        substream: OutboundFramed<NegotiatedSubstream, TSpec>,
+        substream: Box<OutboundFramed<NegotiatedSubstream, TSpec>>,
         /// Keeps track of the actual request sent.
         request: RPCRequest<TSpec>,
     },
     /// Closing an outbound substream>
-    Closing(OutboundFramed<NegotiatedSubstream, TSpec>),
+    Closing(Box<OutboundFramed<NegotiatedSubstream, TSpec>>),
     /// Temporary state during processing
     Poisoned,
 }
@@ -326,7 +326,7 @@ where
         if matches!(self.state, HandlerState::Active) {
             debug!(self.log, "Starting handler shutdown"; "unsent_queued_requests" => self.dial_queue.len());
             // we now drive to completion communications already dialed/established
-            for (id, req) in self.dial_queue.pop() {
+            while let Some((id, req)) = self.dial_queue.pop() {
                 self.pending_errors.push(HandlerErr::Outbound {
                     id,
                     proto: req.protocol(),
@@ -551,7 +551,7 @@ where
                 self.current_inbound_substream_id,
                 Duration::from_secs(RESPONSE_TIMEOUT),
             );
-            let awaiting_stream = InboundSubstreamState::ResponseIdle(substream);
+            let awaiting_stream = InboundSubstreamState::ResponseIdle(Box::new(substream));
             self.inbound_substreams.insert(
                 self.current_inbound_substream_id,
                 (awaiting_stream, Some(delay_key), req.protocol()),
@@ -593,7 +593,7 @@ where
                 Duration::from_secs(RESPONSE_TIMEOUT),
             );
             let awaiting_stream = OutboundSubstreamState::RequestPendingResponse {
-                substream: out,
+                substream: Box::new(out),
                 request,
             };
             let expected_responses = if expected_responses > 1 {
@@ -833,7 +833,7 @@ where
                                                     // await flush
                                                     entry.get_mut().0 =
                                                     InboundSubstreamState::ResponsePendingFlush {
-                                                        substream,
+                                                        substream: substream,
                                                         closing,
                                                     };
                                                     drive_stream_further = true;
@@ -853,7 +853,7 @@ where
                                                     } else {
                                                         // check for queued chunks and update the stream
                                                         entry.get_mut().0 = apply_queued_responses(
-                                                            substream,
+                                                            *substream,
                                                             &mut self
                                                                 .queued_outbound_items
                                                                 .get_mut(&request_id),
@@ -908,7 +908,7 @@ where
                                         } else {
                                             // check for queued chunks and update the stream
                                             entry.get_mut().0 = apply_queued_responses(
-                                                substream,
+                                                *substream,
                                                 &mut self
                                                     .queued_outbound_items
                                                     .get_mut(&request_id),
@@ -942,7 +942,7 @@ where
                             InboundSubstreamState::ResponseIdle(substream) => {
                                 if !deactivated {
                                     entry.get_mut().0 = apply_queued_responses(
-                                        substream,
+                                        *substream,
                                         &mut self.queued_outbound_items.get_mut(&request_id),
                                         &mut drive_stream_further,
                                     );
@@ -1190,10 +1190,10 @@ fn apply_queued_responses<TSpec: EthSpec>(
             match queue.remove(0) {
                 RPCCodedResponse::StreamTermination(_) => {
                     // close the stream if this is a stream termination
-                    InboundSubstreamState::Closing(substream)
+                    InboundSubstreamState::Closing(Box::new(substream))
                 }
                 chunk => InboundSubstreamState::ResponsePendingSend {
-                    substream,
+                    substream: Box::new(substream),
                     message: chunk,
                     closing: false,
                 },
@@ -1201,7 +1201,7 @@ fn apply_queued_responses<TSpec: EthSpec>(
         }
         _ => {
             // no items queued set to idle
-            InboundSubstreamState::ResponseIdle(substream)
+            InboundSubstreamState::ResponseIdle(Box::new(substream))
         }
     }
 }
diff --git a/beacon_node/eth2_libp2p/src/service.rs b/beacon_node/eth2_libp2p/src/service.rs
index 130c495a3..ea5cf8bd8 100644
--- a/beacon_node/eth2_libp2p/src/service.rs
+++ b/beacon_node/eth2_libp2p/src/service.rs
@@ -106,7 +106,12 @@ impl<TSpec: EthSpec> Service<TSpec> {
         ));
 
         info!(log, "Libp2p Service"; "peer_id" => format!("{:?}", enr.peer_id()));
-        debug!(log, "Attempting to open listening ports"; "address" => format!("{}", config.listen_address), "tcp_port" => config.libp2p_port, "udp_port" => config.discovery_port);
+        let discovery_string = if config.disable_discovery {
+            "None".into()
+        } else {
+            config.discovery_port.to_string()
+        };
+        debug!(log, "Attempting to open listening ports"; "address" => format!("{}", config.listen_address), "tcp_port" => config.libp2p_port, "udp_port" => discovery_string);
 
         let mut swarm = {
             // Set up the transport - tcp/ws with noise and yamux/mplex
diff --git a/beacon_node/network/src/attestation_service/mod.rs b/beacon_node/network/src/attestation_service/mod.rs
index 7ed904df4..5ee201ff9 100644
--- a/beacon_node/network/src/attestation_service/mod.rs
+++ b/beacon_node/network/src/attestation_service/mod.rs
@@ -260,7 +260,7 @@ impl<T: BeaconChainTypes> AttestationService<T> {
     /// verification, re-propagates and returns false.
     pub fn should_process_attestation(
         &mut self,
-        subnet: &SubnetId,
+        subnet: SubnetId,
         attestation: &Attestation<T::EthSpec>,
     ) -> bool {
         let exact_subnet = ExactSubnet {
diff --git a/beacon_node/network/src/router/mod.rs b/beacon_node/network/src/router/mod.rs
index bc77f6cee..05799dc66 100644
--- a/beacon_node/network/src/router/mod.rs
+++ b/beacon_node/network/src/router/mod.rs
@@ -218,11 +218,9 @@ impl<T: BeaconChainTypes> Router<T> {
         match gossip_message {
             // Attestations should never reach the router.
             PubsubMessage::AggregateAndProofAttestation(aggregate_and_proof) => {
-                if let Some(gossip_verified) =
-                    self.processor.verify_aggregated_attestation_for_gossip(
-                        peer_id.clone(),
-                        *aggregate_and_proof.clone(),
-                    )
+                if let Some(gossip_verified) = self
+                    .processor
+                    .verify_aggregated_attestation_for_gossip(peer_id.clone(), *aggregate_and_proof)
                 {
                     self.propagate_message(id, peer_id.clone());
                     self.processor
diff --git a/beacon_node/network/src/service.rs b/beacon_node/network/src/service.rs
index 383a4d276..4a410cef9 100644
--- a/beacon_node/network/src/service.rs
+++ b/beacon_node/network/src/service.rs
@@ -294,7 +294,7 @@ fn spawn_service<T: BeaconChainTypes>(
                                 match message {
                                     // attestation information gets processed in the attestation service
                                     PubsubMessage::Attestation(ref subnet_and_attestation) => {
-                                        let subnet = &subnet_and_attestation.0;
+                                        let subnet = subnet_and_attestation.0;
                                         let attestation = &subnet_and_attestation.1;
                                         // checks if we have an aggregator for the slot. If so, we process
                                         // the attestation
diff --git a/beacon_node/network/src/sync/manager.rs b/beacon_node/network/src/sync/manager.rs
index eea70305e..3040fc245 100644
--- a/beacon_node/network/src/sync/manager.rs
+++ b/beacon_node/network/src/sync/manager.rs
@@ -534,7 +534,7 @@ impl<T: BeaconChainTypes> SyncManager<T> {
 
         // otherwise, this is a range sync issue, notify the range sync
         self.range_sync
-            .inject_error(&mut self.network, peer_id.clone(), request_id);
+            .inject_error(&mut self.network, peer_id, request_id);
     }
 
     fn peer_disconnect(&mut self, peer_id: &PeerId) {
@@ -672,7 +672,7 @@ impl<T: BeaconChainTypes> SyncManager<T> {
                         "last_peer" => format!("{:?}", parent_request.last_submitted_peer),
                     );
                     self.network
-                        .downvote_peer(parent_request.last_submitted_peer.clone());
+                        .downvote_peer(parent_request.last_submitted_peer);
                     return;
                 }
                 Err(e) => {
@@ -682,7 +682,7 @@ impl<T: BeaconChainTypes> SyncManager<T> {
                         "last_peer" => format!("{:?}", parent_request.last_submitted_peer),
                     );
                     self.network
-                        .downvote_peer(parent_request.last_submitted_peer.clone());
+                        .downvote_peer(parent_request.last_submitted_peer);
                     return;
                 }
             }
diff --git a/beacon_node/rest_api/src/validator.rs b/beacon_node/rest_api/src/validator.rs
index 7c1f1bdc0..08df5200f 100644
--- a/beacon_node/rest_api/src/validator.rs
+++ b/beacon_node/rest_api/src/validator.rs
@@ -482,6 +482,7 @@ pub async fn publish_attestations<T: BeaconChainTypes>(
 
 /// Processes an unaggregrated attestation that was included in a list of attestations with the
 /// index `i`.
+#[allow(clippy::redundant_clone)] // false positives in this function.
 fn process_unaggregated_attestation<T: BeaconChainTypes>(
     beacon_chain: &BeaconChain<T>,
     network_chan: NetworkChannel<T::EthSpec>,
@@ -549,6 +550,7 @@ fn process_unaggregated_attestation<T: BeaconChainTypes>(
 }
 
 /// HTTP Handler to publish an Attestation, which has been signed by a validator.
+#[allow(clippy::redundant_clone)] // false positives in this function.
 pub async fn publish_aggregate_and_proofs<T: BeaconChainTypes>(
     req: Request<Body>,
     beacon_chain: Arc<BeaconChain<T>>,
@@ -596,6 +598,7 @@ pub async fn publish_aggregate_and_proofs<T: BeaconChainTypes>(
 
 /// Processes an aggregrated attestation that was included in a list of attestations with the index
 /// `i`.
+#[allow(clippy::redundant_clone)] // false positives in this function.
 fn process_aggregated_attestation<T: BeaconChainTypes>(
     beacon_chain: &BeaconChain<T>,
     network_chan: NetworkChannel<T::EthSpec>,
diff --git a/beacon_node/src/cli.rs b/beacon_node/src/cli.rs
index 50f635d0d..07cc44fab 100644
--- a/beacon_node/src/cli.rs
+++ b/beacon_node/src/cli.rs
@@ -61,7 +61,7 @@ pub fn cli_app<'a, 'b>() -> App<'a, 'b> {
                 .takes_value(true),
         )
         .arg(
-            Arg::with_name("max_peers")
+            Arg::with_name("max-peers")
                 .long("max-peers")
                 .help("The maximum number of peers.")
                 .default_value("50")
@@ -125,6 +125,13 @@ pub fn cli_app<'a, 'b>() -> App<'a, 'b> {
                        without an ENR.")
                 .takes_value(true),
         )
+        .arg(
+            Arg::with_name("disable-discovery")
+                .long("disable-discovery")
+                .help("Disables the discv5 discovery protocol. The node will not search for new peers or participate in the discovery protocol.")
+                .takes_value(false),
+        )
+
         /* REST API related arguments */
         .arg(
             Arg::with_name("http")
diff --git a/beacon_node/src/config.rs b/beacon_node/src/config.rs
index f794f8886..5cb029a36 100644
--- a/beacon_node/src/config.rs
+++ b/beacon_node/src/config.rs
@@ -7,14 +7,11 @@ use eth2_testnet_config::Eth2TestnetConfig;
 use slog::{crit, info, Logger};
 use ssz::Encode;
 use std::fs;
-use std::fs::File;
-use std::io::prelude::*;
 use std::net::{IpAddr, Ipv4Addr, ToSocketAddrs};
 use std::net::{TcpListener, UdpSocket};
 use std::path::PathBuf;
 use types::{ChainSpec, EthSpec};
 
-pub const CLIENT_CONFIG_FILENAME: &str = "beacon-node.toml";
 pub const BEACON_NODE_DIR: &str = "beacon";
 pub const NETWORK_DIR: &str = "network";
 
@@ -42,7 +39,7 @@ pub fn get_config<E: EthSpec>(
         fs::remove_dir_all(
             client_config
                 .get_db_path()
-                .ok_or("Failed to get db_path".to_string())?,
+                .ok_or_else(|| "Failed to get db_path".to_string())?,
         )
         .map_err(|err| format!("Failed to remove chain_db: {}", err))?;
 
@@ -50,7 +47,7 @@ pub fn get_config<E: EthSpec>(
         fs::remove_dir_all(
             client_config
                 .get_freezer_db_path()
-                .ok_or("Failed to get freezer db path".to_string())?,
+                .ok_or_else(|| "Failed to get freezer db path".to_string())?,
         )
         .map_err(|err| format!("Failed to remove chain_db: {}", err))?;
 
@@ -72,17 +69,7 @@ pub fn get_config<E: EthSpec>(
     log_dir.pop();
     info!(log, "Data directory initialised"; "datadir" => format!("{}",log_dir.into_os_string().into_string().expect("Datadir should be a valid os string")));
 
-    // Load the client config, if it exists .
-    let config_file_path = client_config.data_dir.join(CLIENT_CONFIG_FILENAME);
-    let config_file_existed = config_file_path.exists();
-    if config_file_existed {
-        client_config = read_from_file(config_file_path.clone())
-            .map_err(|e| format!("Unable to parse {:?} file: {:?}", config_file_path, e))?
-            .ok_or_else(|| format!("{:?} file does not exist", config_file_path))?;
-    } else {
-        client_config.spec_constants = spec_constants.into();
-    }
-
+    client_config.spec_constants = spec_constants.into();
     client_config.testnet_dir = get_testnet_dir(cli_args);
 
     /*
@@ -208,6 +195,11 @@ pub fn get_config<E: EthSpec>(
         client_config.network.discv5_config.enr_update = false;
     }
 
+    if cli_args.is_present("disable-discovery") {
+        client_config.network.disable_discovery = true;
+        slog::warn!(log, "Discovery is disabled. New peers will not be found");
+    }
+
     /*
      * Http server
      */
@@ -295,7 +287,7 @@ pub fn get_config<E: EthSpec>(
 
     if spec_constants != client_config.spec_constants {
         crit!(log, "Specification constants do not match.";
-              "client_config" => client_config.spec_constants.to_string(),
+              "client_config" => client_config.spec_constants,
               "eth2_config" => spec_constants
         );
         return Err("Specification constant mismatch".into());
@@ -351,10 +343,6 @@ pub fn get_config<E: EthSpec>(
         client_config.genesis = ClientGenesis::DepositContract;
     }
 
-    if !config_file_existed {
-        write_to_file(config_file_path, &client_config)?;
-    }
-
     Ok(client_config)
 }
 
@@ -436,42 +424,3 @@ pub fn unused_port(transport: &str) -> Result<u16, String> {
     };
     Ok(local_addr.port())
 }
-
-/// Write a configuration to file.
-pub fn write_to_file<T>(path: PathBuf, config: &T) -> Result<(), String>
-where
-    T: Default + serde::de::DeserializeOwned + serde::Serialize,
-{
-    if let Ok(mut file) = File::create(path.clone()) {
-        let toml_encoded = toml::to_string(&config).map_err(|e| {
-            format!(
-                "Failed to write configuration to {:?}. Error: {:?}",
-                path, e
-            )
-        })?;
-        file.write_all(toml_encoded.as_bytes())
-            .unwrap_or_else(|_| panic!("Unable to write to {:?}", path));
-    }
-
-    Ok(())
-}
-
-/// Loads a `ClientConfig` from file. If unable to load from file, generates a default
-/// configuration and saves that as a sample file.
-pub fn read_from_file<T>(path: PathBuf) -> Result<Option<T>, String>
-where
-    T: Default + serde::de::DeserializeOwned + serde::Serialize,
-{
-    if let Ok(mut file) = File::open(path.clone()) {
-        let mut contents = String::new();
-        file.read_to_string(&mut contents)
-            .map_err(|e| format!("Unable to read {:?}. Error: {:?}", path, e))?;
-
-        let config = toml::from_str(&contents)
-            .map_err(|e| format!("Unable to parse {:?}: {:?}", path, e))?;
-
-        Ok(Some(config))
-    } else {
-        Ok(None)
-    }
-}
diff --git a/common/eth2_testnet_config/build.rs b/common/eth2_testnet_config/build.rs
index d2970cb1b..38fab42a7 100644
--- a/common/eth2_testnet_config/build.rs
+++ b/common/eth2_testnet_config/build.rs
@@ -10,12 +10,13 @@ const TESTNET_ID: &str = "altona";
 
 fn main() {
     if !base_dir().exists() {
-        std::fs::create_dir_all(base_dir()).expect(&format!("Unable to create {:?}", base_dir()));
+        std::fs::create_dir_all(base_dir())
+            .unwrap_or_else(|_| panic!("Unable to create {:?}", base_dir()));
 
         match get_all_files() {
             Ok(()) => (),
             Err(e) => {
-                std::fs::remove_dir_all(base_dir()).expect(&format!(
+                std::fs::remove_dir_all(base_dir()).unwrap_or_else(|_| panic!(
                     "{}. Failed to remove {:?}, please remove the directory manually because it may contains incomplete testnet data.",
                     e,
                     base_dir(),
diff --git a/common/validator_dir/src/builder.rs b/common/validator_dir/src/builder.rs
index 9f29f3dc0..a33d910b5 100644
--- a/common/validator_dir/src/builder.rs
+++ b/common/validator_dir/src/builder.rs
@@ -182,7 +182,7 @@ impl<'a> Builder<'a> {
                 //
                 // This allows us to know the RLP data for the eth1 transaction without needing to know
                 // the withdrawal/voting keypairs again at a later date.
-                let path = dir.clone().join(ETH1_DEPOSIT_DATA_FILE);
+                let path = dir.join(ETH1_DEPOSIT_DATA_FILE);
                 if path.exists() {
                     return Err(Error::DepositDataAlreadyExists(path));
                 } else {
@@ -191,7 +191,7 @@ impl<'a> Builder<'a> {
                         .write(true)
                         .read(true)
                         .create(true)
-                        .open(path.clone())
+                        .open(path)
                         .map_err(Error::UnableToSaveDepositData)?
                         .write_all(hex.as_bytes())
                         .map_err(Error::UnableToSaveDepositData)?
@@ -200,7 +200,7 @@ impl<'a> Builder<'a> {
                 // Save `ETH1_DEPOSIT_AMOUNT_FILE` to file.
                 //
                 // This allows us to know the intended deposit amount at a later date.
-                let path = dir.clone().join(ETH1_DEPOSIT_AMOUNT_FILE);
+                let path = dir.join(ETH1_DEPOSIT_AMOUNT_FILE);
                 if path.exists() {
                     return Err(Error::DepositAmountAlreadyExists(path));
                 } else {
@@ -208,7 +208,7 @@ impl<'a> Builder<'a> {
                         .write(true)
                         .read(true)
                         .create(true)
-                        .open(path.clone())
+                        .open(path)
                         .map_err(Error::UnableToSaveDepositAmount)?
                         .write_all(format!("{}", amount).as_bytes())
                         .map_err(Error::UnableToSaveDepositAmount)?
@@ -220,29 +220,24 @@ impl<'a> Builder<'a> {
                 // Write the withdrawal password to file.
                 write_password_to_file(
                     self.password_dir
-                        .clone()
                         .join(withdrawal_keypair.pk.as_hex_string()),
                     withdrawal_password.as_bytes(),
                 )?;
 
                 // Write the withdrawal keystore to file.
-                write_keystore_to_file(
-                    dir.clone().join(WITHDRAWAL_KEYSTORE_FILE),
-                    &withdrawal_keystore,
-                )?;
+                write_keystore_to_file(dir.join(WITHDRAWAL_KEYSTORE_FILE), &withdrawal_keystore)?;
             }
         }
 
         // Write the voting password to file.
         write_password_to_file(
             self.password_dir
-                .clone()
                 .join(format!("0x{}", voting_keystore.pubkey())),
             voting_password.as_bytes(),
         )?;
 
         // Write the voting keystore to file.
-        write_keystore_to_file(dir.clone().join(VOTING_KEYSTORE_FILE), &voting_keystore)?;
+        write_keystore_to_file(dir.join(VOTING_KEYSTORE_FILE), &voting_keystore)?;
 
         ValidatorDir::open(dir).map_err(Error::UnableToOpenDir)
     }
@@ -257,7 +252,7 @@ fn write_keystore_to_file(path: PathBuf, keystore: &Keystore) -> Result<(), Erro
             .write(true)
             .read(true)
             .create_new(true)
-            .open(path.clone())
+            .open(path)
             .map_err(Error::UnableToSaveKeystore)?;
 
         keystore.to_json_writer(file).map_err(Into::into)
diff --git a/consensus/fork_choice/src/fork_choice.rs b/consensus/fork_choice/src/fork_choice.rs
index 01080a62d..13d167936 100644
--- a/consensus/fork_choice/src/fork_choice.rs
+++ b/consensus/fork_choice/src/fork_choice.rs
@@ -190,7 +190,7 @@ fn dequeue_attestations(
         queued_attestations
             .iter()
             .position(|a| a.slot >= current_slot)
-            .unwrap_or(queued_attestations.len()),
+            .unwrap_or_else(|| queued_attestations.len()),
     );
 
     std::mem::replace(queued_attestations, remaining)
@@ -286,6 +286,7 @@ where
     /// Equivalent to:
     ///
     /// https://github.com/ethereum/eth2.0-specs/blob/v0.12.1/specs/phase0/fork-choice.md#get_ancestor
+    #[allow(clippy::if_same_then_else)]
     fn get_ancestor(
         &self,
         block_root: Hash256,
diff --git a/consensus/proto_array/src/fork_choice_test_definition.rs b/consensus/proto_array/src/fork_choice_test_definition.rs
index cbb905072..6e1bd970b 100644
--- a/consensus/proto_array/src/fork_choice_test_definition.rs
+++ b/consensus/proto_array/src/fork_choice_test_definition.rs
@@ -80,10 +80,9 @@ impl ForkChoiceTestDefinition {
                             finalized_epoch,
                             &justified_state_balances,
                         )
-                        .expect(&format!(
-                            "find_head op at index {} returned error",
-                            op_index
-                        ));
+                        .unwrap_or_else(|_| {
+                            panic!("find_head op at index {} returned error", op_index)
+                        });
 
                     assert_eq!(
                         head, expected_head,
@@ -129,10 +128,12 @@ impl ForkChoiceTestDefinition {
                         justified_epoch,
                         finalized_epoch,
                     };
-                    fork_choice.process_block(block).expect(&format!(
-                        "process_block op at index {} returned error",
-                        op_index
-                    ));
+                    fork_choice.process_block(block).unwrap_or_else(|e| {
+                        panic!(
+                            "process_block op at index {} returned error: {:?}",
+                            op_index, e
+                        )
+                    });
                     check_bytes_round_trip(&fork_choice);
                 }
                 Operation::ProcessAttestation {
@@ -142,10 +143,12 @@ impl ForkChoiceTestDefinition {
                 } => {
                     fork_choice
                         .process_attestation(validator_index, block_root, target_epoch)
-                        .expect(&format!(
-                            "process_attestation op at index {} returned error",
-                            op_index
-                        ));
+                        .unwrap_or_else(|_| {
+                            panic!(
+                                "process_attestation op at index {} returned error",
+                                op_index
+                            )
+                        });
                     check_bytes_round_trip(&fork_choice);
                 }
                 Operation::Prune {
diff --git a/consensus/proto_array/src/fork_choice_test_definition/ffg_updates.rs b/consensus/proto_array/src/fork_choice_test_definition/ffg_updates.rs
index 9dd9417f2..4b7eb25d7 100644
--- a/consensus/proto_array/src/fork_choice_test_definition/ffg_updates.rs
+++ b/consensus/proto_array/src/fork_choice_test_definition/ffg_updates.rs
@@ -91,7 +91,7 @@ pub fn get_ffg_case_01_test_definition() -> ForkChoiceTestDefinition {
         justified_epoch: Epoch::new(2),
         justified_root: get_hash(3),
         finalized_epoch: Epoch::new(1),
-        justified_state_balances: balances.clone(),
+        justified_state_balances: balances,
         expected_head: get_hash(3),
     });
 
@@ -421,7 +421,7 @@ pub fn get_ffg_case_02_test_definition() -> ForkChoiceTestDefinition {
         justified_epoch: Epoch::new(3),
         justified_root: get_hash(2),
         finalized_epoch: Epoch::new(0),
-        justified_state_balances: balances.clone(),
+        justified_state_balances: balances,
     });
 
     // END OF TESTS
diff --git a/consensus/proto_array/src/fork_choice_test_definition/no_votes.rs b/consensus/proto_array/src/fork_choice_test_definition/no_votes.rs
index 279cde52c..e42abe288 100644
--- a/consensus/proto_array/src/fork_choice_test_definition/no_votes.rs
+++ b/consensus/proto_array/src/fork_choice_test_definition/no_votes.rs
@@ -212,7 +212,7 @@ pub fn get_no_votes_test_definition() -> ForkChoiceTestDefinition {
             justified_epoch: Epoch::new(2),
             justified_root: get_hash(5),
             finalized_epoch: Epoch::new(1),
-            justified_state_balances: balances.clone(),
+            justified_state_balances: balances,
             expected_head: get_hash(6),
         },
     ];
diff --git a/consensus/proto_array/src/fork_choice_test_definition/votes.rs b/consensus/proto_array/src/fork_choice_test_definition/votes.rs
index 4f8091269..ac9513c5f 100644
--- a/consensus/proto_array/src/fork_choice_test_definition/votes.rs
+++ b/consensus/proto_array/src/fork_choice_test_definition/votes.rs
@@ -673,7 +673,7 @@ pub fn get_votes_test_definition() -> ForkChoiceTestDefinition {
         justified_epoch: Epoch::new(2),
         justified_root: get_hash(5),
         finalized_epoch: Epoch::new(2),
-        justified_state_balances: balances.clone(),
+        justified_state_balances: balances,
         expected_head: get_hash(11),
     });
 
diff --git a/consensus/types/src/attester_slashing.rs b/consensus/types/src/attester_slashing.rs
index 7deaf56f9..876bb88e6 100644
--- a/consensus/types/src/attester_slashing.rs
+++ b/consensus/types/src/attester_slashing.rs
@@ -10,20 +10,8 @@ use tree_hash_derive::TreeHash;
 ///
 /// Spec v0.12.1
 #[cfg_attr(feature = "arbitrary-fuzz", derive(arbitrary::Arbitrary))]
-#[derive(
-    Derivative,
-    Debug,
-    PartialEq,
-    Eq,
-    Clone,
-    Serialize,
-    Deserialize,
-    Encode,
-    Decode,
-    TreeHash,
-    TestRandom,
-)]
-#[derivative(Hash(bound = "T: EthSpec"))]
+#[derive(Derivative, Debug, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
+#[derivative(PartialEq, Eq, Hash(bound = "T: EthSpec"))]
 #[serde(bound = "T: EthSpec")]
 pub struct AttesterSlashing<T: EthSpec> {
     pub attestation_1: IndexedAttestation<T>,
diff --git a/consensus/types/src/indexed_attestation.rs b/consensus/types/src/indexed_attestation.rs
index cb9f5eacc..341db1807 100644
--- a/consensus/types/src/indexed_attestation.rs
+++ b/consensus/types/src/indexed_attestation.rs
@@ -1,4 +1,5 @@
 use crate::{test_utils::TestRandom, AggregateSignature, AttestationData, EthSpec, VariableList};
+use derivative::Derivative;
 use serde_derive::{Deserialize, Serialize};
 use ssz::Encode;
 use ssz_derive::{Decode, Encode};
@@ -12,9 +13,8 @@ use tree_hash_derive::TreeHash;
 ///
 /// Spec v0.12.1
 #[cfg_attr(feature = "arbitrary-fuzz", derive(arbitrary::Arbitrary))]
-#[derive(
-    Debug, PartialEq, Eq, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom,
-)]
+#[derive(Derivative, Debug, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
+#[derivative(PartialEq, Eq)] // to satisfy Clippy's lint about `Hash`
 #[serde(bound = "T: EthSpec")]
 pub struct IndexedAttestation<T: EthSpec> {
     /// Lists validator registry indices, not committee indices.
diff --git a/consensus/types/src/test_utils/builders/testing_attester_slashing_builder.rs b/consensus/types/src/test_utils/builders/testing_attester_slashing_builder.rs
index 05aabbf18..356f10ec8 100644
--- a/consensus/types/src/test_utils/builders/testing_attester_slashing_builder.rs
+++ b/consensus/types/src/test_utils/builders/testing_attester_slashing_builder.rs
@@ -47,11 +47,11 @@ impl TestingAttesterSlashingBuilder {
         };
 
         let data_2 = if test_task == AttesterSlashingTestTask::NotSlashable {
-            AttestationData { ..data_1.clone() }
+            data_1.clone()
         } else {
             AttestationData {
                 target: checkpoint_2,
-                ..data_1.clone()
+                ..data_1
             }
         };
 
diff --git a/crypto/eth2_keystore/src/keystore.rs b/crypto/eth2_keystore/src/keystore.rs
index 8d68265a7..b23751f82 100644
--- a/crypto/eth2_keystore/src/keystore.rs
+++ b/crypto/eth2_keystore/src/keystore.rs
@@ -190,7 +190,7 @@ impl Keystore {
 
         let keypair = keypair_from_secret(plain_text.as_bytes())?;
         // Verify that the derived `PublicKey` matches `self`.
-        if keypair.pk.as_hex_string()[2..].to_string() != self.json.pubkey {
+        if keypair.pk.as_hex_string()[2..] != self.json.pubkey {
             return Err(Error::PublicKeyMismatch);
         }
 
diff --git a/lighthouse/environment/src/lib.rs b/lighthouse/environment/src/lib.rs
index aeec4dbed..3d26aa6d2 100644
--- a/lighthouse/environment/src/lib.rs
+++ b/lighthouse/environment/src/lib.rs
@@ -283,7 +283,7 @@ impl<E: EthSpec> Environment<E> {
             executor: TaskExecutor {
                 exit: self.exit.clone(),
                 handle: self.runtime().handle().clone(),
-                log: self.log.new(o!("service" => service_name.clone())),
+                log: self.log.new(o!("service" => service_name)),
             },
             eth_spec_instance: self.eth_spec_instance.clone(),
             eth2_config: self.eth2_config.clone(),
diff --git a/validator_client/src/duties_service.rs b/validator_client/src/duties_service.rs
index d68ccc008..d5a2c2d48 100644
--- a/validator_client/src/duties_service.rs
+++ b/validator_client/src/duties_service.rs
@@ -232,12 +232,12 @@ impl DutiesStore {
             .collect()
     }
 
-    fn is_aggregator(&self, validator_pubkey: &PublicKey, epoch: &Epoch) -> Option<bool> {
+    fn is_aggregator(&self, validator_pubkey: &PublicKey, epoch: Epoch) -> Option<bool> {
         Some(
             self.store
                 .read()
                 .get(validator_pubkey)?
-                .get(epoch)?
+                .get(&epoch)?
                 .selection_proof
                 .is_some(),
         )
@@ -604,7 +604,7 @@ impl<T: SlotClock + 'static, E: EthSpec> DutiesService<T, E> {
 
                 // The selection proof is computed on `store.insert`, so it's necessary to check
                 // with the store that the validator is an aggregator.
-                let is_aggregator = self.store.is_aggregator(&validator_pubkey, &epoch)?;
+                let is_aggregator = self.store.is_aggregator(&validator_pubkey, epoch)?;
 
                 if outcome.is_subscription_candidate() {
                     Some(ValidatorSubscription {