diff --git a/beacon_node/beacon_chain/src/beacon_chain.rs b/beacon_node/beacon_chain/src/beacon_chain.rs
index 6036ce397..bfe7ca143 100644
--- a/beacon_node/beacon_chain/src/beacon_chain.rs
+++ b/beacon_node/beacon_chain/src/beacon_chain.rs
@@ -1602,7 +1602,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                 // This method is called for API and gossip attestations, so this covers all unaggregated attestation events
                 if let Some(event_handler) = self.event_handler.as_ref() {
                     if event_handler.has_attestation_subscribers() {
-                        event_handler.register(EventKind::Attestation(v.attestation().clone()));
+                        event_handler
+                            .register(EventKind::Attestation(Box::new(v.attestation().clone())));
                     }
                 }
                 metrics::inc_counter(&metrics::UNAGGREGATED_ATTESTATION_PROCESSING_SUCCESSES);
@@ -1638,7 +1639,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             // This method is called for API and gossip attestations, so this covers all aggregated attestation events
             if let Some(event_handler) = self.event_handler.as_ref() {
                 if event_handler.has_attestation_subscribers() {
-                    event_handler.register(EventKind::Attestation(v.attestation().clone()));
+                    event_handler
+                        .register(EventKind::Attestation(Box::new(v.attestation().clone())));
                 }
             }
             metrics::inc_counter(&metrics::AGGREGATED_ATTESTATION_PROCESSING_SUCCESSES);
diff --git a/beacon_node/beacon_chain/src/state_advance_timer.rs b/beacon_node/beacon_chain/src/state_advance_timer.rs
index 947e8c38e..6a3c3ea00 100644
--- a/beacon_node/beacon_chain/src/state_advance_timer.rs
+++ b/beacon_node/beacon_chain/src/state_advance_timer.rs
@@ -41,9 +41,17 @@ const MAX_ADVANCE_DISTANCE: u64 = 4;
 enum Error {
     BeaconChain(BeaconChainError),
     HeadMissingFromSnapshotCache(Hash256),
-    MaxDistanceExceeded { current_slot: Slot, head_slot: Slot },
-    StateAlreadyAdvanced { block_root: Hash256 },
-    BadStateSlot { state_slot: Slot, block_slot: Slot },
+    MaxDistanceExceeded {
+        current_slot: Slot,
+        head_slot: Slot,
+    },
+    StateAlreadyAdvanced {
+        block_root: Hash256,
+    },
+    BadStateSlot {
+        _state_slot: Slot,
+        _block_slot: Slot,
+    },
 }
 
 impl From<BeaconChainError> for Error {
@@ -224,8 +232,8 @@ fn advance_head<T: BeaconChainTypes>(
         // Advancing more than one slot without storing the intermediate state would corrupt the
         // database. Future works might store temporary, intermediate states inside this function.
         return Err(Error::BadStateSlot {
-            block_slot: head_slot,
-            state_slot: state.slot(),
+            _block_slot: head_slot,
+            _state_slot: state.slot(),
         });
     };
 
diff --git a/beacon_node/beacon_chain/src/validator_pubkey_cache.rs b/beacon_node/beacon_chain/src/validator_pubkey_cache.rs
index 2dbe8ce7b..da877cf4e 100644
--- a/beacon_node/beacon_chain/src/validator_pubkey_cache.rs
+++ b/beacon_node/beacon_chain/src/validator_pubkey_cache.rs
@@ -243,8 +243,8 @@ enum Error {
     /// The file read from disk does not have a contiguous list of validator public keys. The file
     /// has become corrupted.
     InconsistentIndex {
-        expected: Option<usize>,
-        found: usize,
+        _expected: Option<usize>,
+        _found: usize,
     },
 }
 
@@ -296,8 +296,8 @@ impl ValidatorPubkeyCacheFile {
                 indices.insert(pubkey, index);
             } else {
                 return Err(Error::InconsistentIndex {
-                    expected,
-                    found: index,
+                    _expected: expected,
+                    _found: index,
                 });
             }
         }
diff --git a/beacon_node/http_api/tests/tests.rs b/beacon_node/http_api/tests/tests.rs
index 95f087130..878af7a03 100644
--- a/beacon_node/http_api/tests/tests.rs
+++ b/beacon_node/http_api/tests/tests.rs
@@ -2310,7 +2310,7 @@ impl ApiTester {
             self.attestations
                 .clone()
                 .into_iter()
-                .map(|attestation| EventKind::Attestation(attestation))
+                .map(|attestation| EventKind::Attestation(Box::new(attestation)))
                 .collect::<Vec<_>>()
                 .as_slice()
         );
diff --git a/beacon_node/network/src/beacon_processor/mod.rs b/beacon_node/network/src/beacon_processor/mod.rs
index c9b4bfa34..7c3d482fa 100644
--- a/beacon_node/network/src/beacon_processor/mod.rs
+++ b/beacon_node/network/src/beacon_processor/mod.rs
@@ -63,7 +63,7 @@ use types::{
     SyncCommitteeMessage, SyncSubnetId,
 };
 use work_reprocessing_queue::{
-    spawn_reprocess_scheduler, QueuedAggregate, QueuedBlock, QueuedUnaggregate, ReadyWork,
+    spawn_reprocess_scheduler, QueuedAggregate, QueuedUnaggregate, ReadyWork,
 };
 
 use worker::{Toolbox, Worker};
@@ -72,6 +72,7 @@ mod tests;
 mod work_reprocessing_queue;
 mod worker;
 
+use crate::beacon_processor::work_reprocessing_queue::QueuedBlock;
 pub use worker::{GossipAggregatePackage, GossipAttestationPackage, ProcessId};
 
 /// The maximum size of the channel for work events to the `BeaconProcessor`.
@@ -574,7 +575,7 @@ impl<T: BeaconChainTypes> std::convert::From<ReadyWork<T>> for WorkEvent<T> {
                 drop_during_sync: false,
                 work: Work::DelayedImportBlock {
                     peer_id,
-                    block: Box::new(block),
+                    block,
                     seen_timestamp,
                 },
             },
diff --git a/beacon_node/network/src/beacon_processor/work_reprocessing_queue.rs b/beacon_node/network/src/beacon_processor/work_reprocessing_queue.rs
index 00b5c009a..299e71c8d 100644
--- a/beacon_node/network/src/beacon_processor/work_reprocessing_queue.rs
+++ b/beacon_node/network/src/beacon_processor/work_reprocessing_queue.rs
@@ -91,7 +91,7 @@ pub struct QueuedAggregate<T: EthSpec> {
 /// A block that arrived early and has been queued for later import.
 pub struct QueuedBlock<T: BeaconChainTypes> {
     pub peer_id: PeerId,
-    pub block: GossipVerifiedBlock<T>,
+    pub block: Box<GossipVerifiedBlock<T>>,
     pub seen_timestamp: Duration,
 }
 
diff --git a/beacon_node/network/src/beacon_processor/worker/gossip_methods.rs b/beacon_node/network/src/beacon_processor/worker/gossip_methods.rs
index 21a8c7618..365d53f49 100644
--- a/beacon_node/network/src/beacon_processor/worker/gossip_methods.rs
+++ b/beacon_node/network/src/beacon_processor/worker/gossip_methods.rs
@@ -121,7 +121,6 @@ pub struct GossipAttestationPackage<E: EthSpec> {
     peer_id: PeerId,
     attestation: Box<Attestation<E>>,
     subnet_id: SubnetId,
-    beacon_block_root: Hash256,
     should_import: bool,
     seen_timestamp: Duration,
 }
@@ -138,7 +137,6 @@ impl<E: EthSpec> GossipAttestationPackage<E> {
         Self {
             message_id,
             peer_id,
-            beacon_block_root: attestation.data.beacon_block_root,
             attestation,
             subnet_id,
             should_import,
@@ -830,7 +828,7 @@ impl<T: BeaconChainTypes> Worker<T> {
                 if reprocess_tx
                     .try_send(ReprocessQueueMessage::EarlyBlock(QueuedBlock {
                         peer_id,
-                        block: verified_block,
+                        block: Box::new(verified_block),
                         seen_timestamp: seen_duration,
                     }))
                     .is_err()
diff --git a/beacon_node/src/config.rs b/beacon_node/src/config.rs
index ab51c218b..ac2ba9d47 100644
--- a/beacon_node/src/config.rs
+++ b/beacon_node/src/config.rs
@@ -226,7 +226,7 @@ pub fn get_config<E: EthSpec>(
         client_config.sync_eth1_chain = true;
         client_config.eth1.endpoints = endpoints
             .split(',')
-            .map(|s| SensitiveUrl::parse(s))
+            .map(SensitiveUrl::parse)
             .collect::<Result<_, _>>()
             .map_err(|e| format!("eth1-endpoints contains an invalid URL {:?}", e))?;
     }
@@ -245,7 +245,7 @@ pub fn get_config<E: EthSpec>(
         client_config.sync_eth1_chain = true;
         client_config.execution_endpoints = endpoints
             .split(',')
-            .map(|s| SensitiveUrl::parse(s))
+            .map(SensitiveUrl::parse)
             .collect::<Result<_, _>>()
             .map(Some)
             .map_err(|e| format!("execution-endpoints contains an invalid URL {:?}", e))?;
diff --git a/common/eth2/src/types.rs b/common/eth2/src/types.rs
index 42131b49c..be65dd877 100644
--- a/common/eth2/src/types.rs
+++ b/common/eth2/src/types.rs
@@ -777,7 +777,7 @@ pub struct SseLateHead {
 #[derive(PartialEq, Debug, Serialize, Clone)]
 #[serde(bound = "T: EthSpec", untagged)]
 pub enum EventKind<T: EthSpec> {
-    Attestation(Attestation<T>),
+    Attestation(Box<Attestation<T>>),
     Block(SseBlock),
     FinalizedCheckpoint(SseFinalizedCheckpoint),
     Head(SseHead),
diff --git a/common/lockfile/src/lib.rs b/common/lockfile/src/lib.rs
index 82e28256f..adb8be7bb 100644
--- a/common/lockfile/src/lib.rs
+++ b/common/lockfile/src/lib.rs
@@ -11,7 +11,7 @@ use std::path::{Path, PathBuf};
 /// outage) caused the lockfile not to be deleted.
 #[derive(Debug)]
 pub struct Lockfile {
-    file: File,
+    _file: File,
     path: PathBuf,
     file_existed: bool,
 }
@@ -43,7 +43,7 @@ impl Lockfile {
             _ => LockfileError::IoError(path.clone(), e),
         })?;
         Ok(Self {
-            file,
+            _file: file,
             path,
             file_existed,
         })
diff --git a/common/logging/src/lib.rs b/common/logging/src/lib.rs
index 6cbf7e00b..eab8e326b 100644
--- a/common/logging/src/lib.rs
+++ b/common/logging/src/lib.rs
@@ -99,7 +99,7 @@ impl<'a> AlignedRecordDecorator<'a> {
 
 impl<'a> Write for AlignedRecordDecorator<'a> {
     fn write(&mut self, buf: &[u8]) -> Result<usize> {
-        if buf.iter().any(|c| is_ascii_control(c)) {
+        if buf.iter().any(u8::is_ascii_control) {
             let filtered = buf
                 .iter()
                 .cloned()
diff --git a/common/monitoring_api/src/lib.rs b/common/monitoring_api/src/lib.rs
index 5eb7ea719..03cdf87c2 100644
--- a/common/monitoring_api/src/lib.rs
+++ b/common/monitoring_api/src/lib.rs
@@ -128,7 +128,7 @@ impl MonitoringHttpClient {
             Error::BeaconMetricsFailed("Beacon metrics require db path".to_string())
         })?;
 
-        let freezer_db_path = self.db_path.as_ref().ok_or_else(|| {
+        let freezer_db_path = self.freezer_db_path.as_ref().ok_or_else(|| {
             Error::BeaconMetricsFailed("Beacon metrics require freezer db path".to_string())
         })?;
         let metrics =
diff --git a/common/validator_dir/src/validator_dir.rs b/common/validator_dir/src/validator_dir.rs
index bfa3e2553..2fabebc74 100644
--- a/common/validator_dir/src/validator_dir.rs
+++ b/common/validator_dir/src/validator_dir.rs
@@ -63,7 +63,7 @@ pub struct Eth1DepositData {
 pub struct ValidatorDir {
     dir: PathBuf,
     #[derivative(PartialEq = "ignore")]
-    lockfile: Lockfile,
+    _lockfile: Lockfile,
 }
 
 impl ValidatorDir {
@@ -85,7 +85,10 @@ impl ValidatorDir {
         let lockfile_path = dir.join(format!("{}.lock", VOTING_KEYSTORE_FILE));
         let lockfile = Lockfile::new(lockfile_path).map_err(Error::LockfileError)?;
 
-        Ok(Self { dir, lockfile })
+        Ok(Self {
+            dir,
+            _lockfile: lockfile,
+        })
     }
 
     /// Returns the `dir` provided to `Self::open`.
diff --git a/consensus/cached_tree_hash/src/cache_arena.rs b/consensus/cached_tree_hash/src/cache_arena.rs
index 9e11134aa..a938d4826 100644
--- a/consensus/cached_tree_hash/src/cache_arena.rs
+++ b/consensus/cached_tree_hash/src/cache_arena.rs
@@ -491,8 +491,8 @@ mod tests {
             subs.push(sub);
         }
 
-        for mut sub in subs.iter_mut() {
-            test_routine(arena, &mut sub);
+        for sub in subs.iter_mut() {
+            test_routine(arena, sub);
         }
     }
 }
diff --git a/consensus/ssz/src/encode.rs b/consensus/ssz/src/encode.rs
index cecd615a8..a46ef80e0 100644
--- a/consensus/ssz/src/encode.rs
+++ b/consensus/ssz/src/encode.rs
@@ -113,7 +113,7 @@ impl<'a> SszEncoder<'a> {
         F: Fn(&mut Vec<u8>),
     {
         if is_ssz_fixed_len {
-            ssz_append(&mut self.buf);
+            ssz_append(self.buf);
         } else {
             self.buf
                 .extend_from_slice(&encode_length(self.offset + self.variable_bytes.len()));
@@ -129,7 +129,7 @@ impl<'a> SszEncoder<'a> {
     pub fn finalize(&mut self) -> &mut Vec<u8> {
         self.buf.append(&mut self.variable_bytes);
 
-        &mut self.buf
+        self.buf
     }
 }
 
diff --git a/consensus/state_processing/src/per_block_processing/tests.rs b/consensus/state_processing/src/per_block_processing/tests.rs
index 78c034caa..f04b0ca90 100644
--- a/consensus/state_processing/src/per_block_processing/tests.rs
+++ b/consensus/state_processing/src/per_block_processing/tests.rs
@@ -187,14 +187,13 @@ fn valid_4_deposits() {
     let harness = get_harness::<MainnetEthSpec>(EPOCH_OFFSET, VALIDATOR_COUNT);
     let mut state = harness.get_current_state();
 
-    let (deposits, mut state) = harness.make_deposits(&mut state, 4, None, None);
+    let (deposits, state) = harness.make_deposits(&mut state, 4, None, None);
     let deposits = VariableList::from(deposits);
 
     let mut head_block = harness.chain.head_beacon_block().unwrap().deconstruct().0;
     *head_block.to_mut().body_mut().deposits_mut() = deposits;
 
-    let result =
-        process_operations::process_deposits(&mut state, head_block.body().deposits(), &spec);
+    let result = process_operations::process_deposits(state, head_block.body().deposits(), &spec);
 
     // Expecting Ok because these are valid deposits.
     assert_eq!(result, Ok(()));
@@ -206,7 +205,7 @@ fn invalid_deposit_deposit_count_too_big() {
     let harness = get_harness::<MainnetEthSpec>(EPOCH_OFFSET, VALIDATOR_COUNT);
     let mut state = harness.get_current_state();
 
-    let (deposits, mut state) = harness.make_deposits(&mut state, 1, None, None);
+    let (deposits, state) = harness.make_deposits(&mut state, 1, None, None);
     let deposits = VariableList::from(deposits);
 
     let mut head_block = harness.chain.head_beacon_block().unwrap().deconstruct().0;
@@ -214,8 +213,7 @@ fn invalid_deposit_deposit_count_too_big() {
 
     let big_deposit_count = NUM_DEPOSITS + 1;
     state.eth1_data_mut().deposit_count = big_deposit_count;
-    let result =
-        process_operations::process_deposits(&mut state, head_block.body().deposits(), &spec);
+    let result = process_operations::process_deposits(state, head_block.body().deposits(), &spec);
 
     // Expecting DepositCountInvalid because we incremented the deposit_count
     assert_eq!(
@@ -233,7 +231,7 @@ fn invalid_deposit_count_too_small() {
     let harness = get_harness::<MainnetEthSpec>(EPOCH_OFFSET, VALIDATOR_COUNT);
     let mut state = harness.get_current_state();
 
-    let (deposits, mut state) = harness.make_deposits(&mut state, 1, None, None);
+    let (deposits, state) = harness.make_deposits(&mut state, 1, None, None);
     let deposits = VariableList::from(deposits);
 
     let mut head_block = harness.chain.head_beacon_block().unwrap().deconstruct().0;
@@ -241,8 +239,7 @@ fn invalid_deposit_count_too_small() {
 
     let small_deposit_count = NUM_DEPOSITS - 1;
     state.eth1_data_mut().deposit_count = small_deposit_count;
-    let result =
-        process_operations::process_deposits(&mut state, head_block.body().deposits(), &spec);
+    let result = process_operations::process_deposits(state, head_block.body().deposits(), &spec);
 
     // Expecting DepositCountInvalid because we decremented the deposit_count
     assert_eq!(
@@ -260,7 +257,7 @@ fn invalid_deposit_bad_merkle_proof() {
     let harness = get_harness::<MainnetEthSpec>(EPOCH_OFFSET, VALIDATOR_COUNT);
     let mut state = harness.get_current_state();
 
-    let (deposits, mut state) = harness.make_deposits(&mut state, 1, None, None);
+    let (deposits, state) = harness.make_deposits(&mut state, 1, None, None);
     let deposits = VariableList::from(deposits);
 
     let mut head_block = harness.chain.head_beacon_block().unwrap().deconstruct().0;
@@ -270,8 +267,7 @@ fn invalid_deposit_bad_merkle_proof() {
     // Manually offsetting deposit count and index to trigger bad merkle proof
     state.eth1_data_mut().deposit_count += 1;
     *state.eth1_deposit_index_mut() += 1;
-    let result =
-        process_operations::process_deposits(&mut state, head_block.body().deposits(), &spec);
+    let result = process_operations::process_deposits(state, head_block.body().deposits(), &spec);
 
     // Expecting BadMerkleProof because the proofs were created with different indices
     assert_eq!(
@@ -289,15 +285,14 @@ fn invalid_deposit_wrong_sig() {
     let harness = get_harness::<MainnetEthSpec>(EPOCH_OFFSET, VALIDATOR_COUNT);
     let mut state = harness.get_current_state();
 
-    let (deposits, mut state) =
+    let (deposits, state) =
         harness.make_deposits(&mut state, 1, None, Some(SignatureBytes::empty()));
     let deposits = VariableList::from(deposits);
 
     let mut head_block = harness.chain.head_beacon_block().unwrap().deconstruct().0;
     *head_block.to_mut().body_mut().deposits_mut() = deposits;
 
-    let result =
-        process_operations::process_deposits(&mut state, head_block.body().deposits(), &spec);
+    let result = process_operations::process_deposits(state, head_block.body().deposits(), &spec);
     // Expecting Ok(()) even though the block signature does not correspond to the correct public key
     assert_eq!(result, Ok(()));
 }
@@ -308,15 +303,14 @@ fn invalid_deposit_invalid_pub_key() {
     let harness = get_harness::<MainnetEthSpec>(EPOCH_OFFSET, VALIDATOR_COUNT);
     let mut state = harness.get_current_state();
 
-    let (deposits, mut state) =
+    let (deposits, state) =
         harness.make_deposits(&mut state, 1, Some(PublicKeyBytes::empty()), None);
     let deposits = VariableList::from(deposits);
 
     let mut head_block = harness.chain.head_beacon_block().unwrap().deconstruct().0;
     *head_block.to_mut().body_mut().deposits_mut() = deposits;
 
-    let result =
-        process_operations::process_deposits(&mut state, head_block.body().deposits(), &spec);
+    let result = process_operations::process_deposits(state, head_block.body().deposits(), &spec);
 
     // Expecting Ok(()) even though we passed in invalid publickeybytes in the public key field of the deposit data.
     assert_eq!(result, Ok(()));
diff --git a/testing/ef_tests/src/cases/fork_choice.rs b/testing/ef_tests/src/cases/fork_choice.rs
index dc1190466..682fa8146 100644
--- a/testing/ef_tests/src/cases/fork_choice.rs
+++ b/testing/ef_tests/src/cases/fork_choice.rs
@@ -62,7 +62,8 @@ pub enum Step<B, A, P> {
 #[derive(Debug, Clone, Deserialize)]
 #[serde(deny_unknown_fields)]
 pub struct Meta {
-    description: String,
+    #[serde(rename(deserialize = "description"))]
+    _description: String,
 }
 
 #[derive(Debug)]
diff --git a/testing/ef_tests/src/cases/genesis_validity.rs b/testing/ef_tests/src/cases/genesis_validity.rs
index e645d69ad..abdc1ed4a 100644
--- a/testing/ef_tests/src/cases/genesis_validity.rs
+++ b/testing/ef_tests/src/cases/genesis_validity.rs
@@ -7,7 +7,8 @@ use types::{BeaconState, EthSpec, ForkName};
 
 #[derive(Debug, Clone, Deserialize)]
 pub struct Metadata {
-    description: String,
+    #[serde(rename(deserialize = "description"))]
+    _description: String,
 }
 
 #[derive(Debug, Clone, Deserialize)]
diff --git a/testing/ef_tests/src/cases/ssz_generic.rs b/testing/ef_tests/src/cases/ssz_generic.rs
index 022da9223..2374ead88 100644
--- a/testing/ef_tests/src/cases/ssz_generic.rs
+++ b/testing/ef_tests/src/cases/ssz_generic.rs
@@ -15,7 +15,8 @@ use types::{BitList, BitVector, FixedVector, ForkName, VariableList};
 #[derive(Debug, Clone, Deserialize)]
 struct Metadata {
     root: String,
-    signing_root: Option<String>,
+    #[serde(rename(deserialize = "signing_root"))]
+    _signing_root: Option<String>,
 }
 
 #[derive(Debug, Clone)]
diff --git a/testing/ef_tests/src/cases/ssz_static.rs b/testing/ef_tests/src/cases/ssz_static.rs
index 732a7d851..d0cc5f9ea 100644
--- a/testing/ef_tests/src/cases/ssz_static.rs
+++ b/testing/ef_tests/src/cases/ssz_static.rs
@@ -10,7 +10,8 @@ use types::{BeaconBlock, BeaconState, ForkName, Hash256, SignedBeaconBlock};
 #[derive(Debug, Clone, Deserialize)]
 struct SszStaticRoots {
     root: String,
-    signing_root: Option<String>,
+    #[serde(rename(deserialize = "signing_root"))]
+    _signing_root: Option<String>,
 }
 
 /// Runner for types that implement `ssz::Decode`.
diff --git a/validator_client/src/config.rs b/validator_client/src/config.rs
index 4b07c72b8..0695012fb 100644
--- a/validator_client/src/config.rs
+++ b/validator_client/src/config.rs
@@ -131,7 +131,7 @@ impl Config {
         if let Some(beacon_nodes) = parse_optional::<String>(cli_args, "beacon-nodes")? {
             config.beacon_nodes = beacon_nodes
                 .split(',')
-                .map(|s| SensitiveUrl::parse(s))
+                .map(SensitiveUrl::parse)
                 .collect::<Result<_, _>>()
                 .map_err(|e| format!("Unable to parse beacon node URL: {:?}", e))?;
         }
diff --git a/validator_client/src/lib.rs b/validator_client/src/lib.rs
index a3ab10316..a721496fc 100644
--- a/validator_client/src/lib.rs
+++ b/validator_client/src/lib.rs
@@ -84,7 +84,6 @@ pub struct ProductionValidatorClient<T: EthSpec> {
     doppelganger_service: Option<Arc<DoppelgangerService>>,
     validator_store: Arc<ValidatorStore<SystemTimeSlotClock, T>>,
     http_api_listen_addr: Option<SocketAddr>,
-    http_metrics_ctx: Option<Arc<http_metrics::Context<T>>>,
     config: Config,
 }
 
@@ -431,7 +430,6 @@ impl<T: EthSpec> ProductionValidatorClient<T> {
             validator_store,
             config,
             http_api_listen_addr: None,
-            http_metrics_ctx,
         })
     }