diff --git a/beacon_chain/beacon_chain_db_immutable.nim b/beacon_chain/beacon_chain_db_immutable.nim
index 9aa13d504..01a2dd01c 100644
--- a/beacon_chain/beacon_chain_db_immutable.nim
+++ b/beacon_chain/beacon_chain_db_immutable.nim
@@ -8,9 +8,6 @@
 {.push raises: [Defect].}
 
 import
-  stew/results,
-  serialization,
-  eth/db/kvstore,
   ./spec/datatypes/[base, altair, bellatrix],
   ./spec/[eth2_ssz_serialization, eth2_merkleization]
 
diff --git a/beacon_chain/consensus_object_pools/attestation_pool.nim b/beacon_chain/consensus_object_pools/attestation_pool.nim
index acc4e495f..eb08a52cc 100644
--- a/beacon_chain/consensus_object_pools/attestation_pool.nim
+++ b/beacon_chain/consensus_object_pools/attestation_pool.nim
@@ -490,7 +490,7 @@ func init(
           if participation_bitmap[validator_index] != 0:
             # If any flag got set, there was an attestation from this validator.
             validator_bits[index_in_committee] = true
-        result.add((slot, committee_index.uint64), validator_bits)
+        result[(slot, committee_index.uint64)] = validator_bits
 
   # This treats all types of rewards as equivalent, which isn't ideal
   update_attestation_pool_cache(
diff --git a/beacon_chain/consensus_object_pools/blockchain_dag.nim b/beacon_chain/consensus_object_pools/blockchain_dag.nim
index fd03a6346..9ec8d9ec1 100644
--- a/beacon_chain/consensus_object_pools/blockchain_dag.nim
+++ b/beacon_chain/consensus_object_pools/blockchain_dag.nim
@@ -21,11 +21,11 @@ export
   eth2_merkleization, eth2_ssz_serialization,
   block_pools_types, results, beacon_chain_db
 
-# https://github.com/ethereum/eth2.0-metrics/blob/master/metrics.md#interop-metrics
+# https://github.com/ethereum/beacon-metrics/blob/master/metrics.md#interop-metrics
 declareGauge beacon_head_root, "Root of the head block of the beacon chain"
 declareGauge beacon_head_slot, "Slot of the head block of the beacon chain"
 
-# https://github.com/ethereum/eth2.0-metrics/blob/master/metrics.md#interop-metrics
+# https://github.com/ethereum/beacon-metrics/blob/master/metrics.md#interop-metrics
 declareGauge beacon_finalized_epoch, "Current finalized epoch" # On epoch transition
 declareGauge beacon_finalized_root, "Current finalized root" # On epoch transition
 declareGauge beacon_current_justified_epoch, "Current justified epoch" # On epoch transition
@@ -542,7 +542,7 @@ proc currentSyncCommitteeForPeriod*(
 
 proc updateBeaconMetrics(
     state: ForkedHashedBeaconState, bid: BlockId, cache: var StateCache) =
-  # https://github.com/ethereum/eth2.0-metrics/blob/master/metrics.md#additional-metrics
+  # https://github.com/ethereum/beacon-metrics/blob/master/metrics.md#additional-metrics
   # both non-negative, so difference can't overflow or underflow int64
 
   beacon_head_root.set(bid.root.toGaugeValue)
diff --git a/beacon_chain/era_db.nim b/beacon_chain/era_db.nim
index 63baff1ba..66b6f4818 100644
--- a/beacon_chain/era_db.nim
+++ b/beacon_chain/era_db.nim
@@ -352,10 +352,10 @@ proc getPartialState(
     false
 
 iterator getBlockIds*(
-    db: EraDB, historical_roots: openArray[Eth2Digest], startSlot: Slot): BlockId =
+    db: EraDB, historical_roots: openArray[Eth2Digest], start_slot: Slot): BlockId =
   var
     state = (ref PartialBeaconState)() # avoid stack overflow
-    slot = startSlot
+    slot = start_slot
 
   while true:
     # `case` ensures we're on a fork for which the `PartialBeaconState`
diff --git a/beacon_chain/eth1/eth1_monitor.nim b/beacon_chain/eth1/eth1_monitor.nim
index db17b32ce..e6a4cf0dc 100644
--- a/beacon_chain/eth1/eth1_monitor.nim
+++ b/beacon_chain/eth1/eth1_monitor.nim
@@ -11,7 +11,7 @@ import
   std/[deques, options, strformat, strutils, sequtils, tables,
        typetraits, uri, json],
   # Nimble packages:
-  chronos, json, metrics, chronicles/timings, stint/endians2,
+  chronos, metrics, chronicles/timings, stint/endians2,
   web3, web3/ethtypes as web3Types, web3/ethhexstrings, web3/engine_api,
   eth/common/eth_types,
   eth/async_utils, stew/[byteutils, objects, shims/hashes],
diff --git a/beacon_chain/fork_choice/proto_array.nim b/beacon_chain/fork_choice/proto_array.nim
index 2bde7d05c..cf6145969 100644
--- a/beacon_chain/fork_choice/proto_array.nim
+++ b/beacon_chain/fork_choice/proto_array.nim
@@ -103,7 +103,7 @@ func init*(T: type ProtoArray,
     indices: {node.root: 0}.toTable()
   )
 
-# https://github.com/ethereum/consensus-specs/blob/v1.1.10/specs/phase0/fork-choice.md#configuration
+# https://github.com/ethereum/consensus-specs/blob/v1.2.0-rc.1/specs/phase0/fork-choice.md#configuration
 # https://github.com/ethereum/consensus-specs/blob/v1.1.10/specs/phase0/fork-choice.md#get_latest_attesting_balance
 const PROPOSER_SCORE_BOOST* = 40
 func calculateProposerBoost(validatorBalances: openArray[Gwei]): int64 =
diff --git a/beacon_chain/gossip_processing/block_processor.nim b/beacon_chain/gossip_processing/block_processor.nim
index 9ca0395ac..bac5e05b7 100644
--- a/beacon_chain/gossip_processing/block_processor.nim
+++ b/beacon_chain/gossip_processing/block_processor.nim
@@ -330,7 +330,7 @@ proc runForkchoiceUpdated(
   # block hash provided by this event is stubbed with
   # `0x0000000000000000000000000000000000000000000000000000000000000000`."
   # and
-  # https://github.com/ethereum/consensus-specs/blob/v1.1.10/specs/bellatrix/validator.md#executionpayload
+  # https://github.com/ethereum/consensus-specs/blob/v1.2.0-rc.1/specs/bellatrix/validator.md#executionpayload
   # notes "`finalized_block_hash` is the hash of the latest finalized execution
   # payload (`Hash32()` if none yet finalized)"
   if headBlockRoot.isZero:
diff --git a/beacon_chain/networking/eth2_network.nim b/beacon_chain/networking/eth2_network.nim
index 8708ab16b..f976a37ce 100644
--- a/beacon_chain/networking/eth2_network.nim
+++ b/beacon_chain/networking/eth2_network.nim
@@ -170,7 +170,7 @@ type
   MounterProc* = proc(network: Eth2Node) {.gcsafe, raises: [Defect, CatchableError].}
   MessageContentPrinter* = proc(msg: pointer): string {.gcsafe, raises: [Defect].}
 
-  # https://github.com/ethereum/consensus-specs/blob/v1.1.10/specs/phase0/p2p-interface.md#goodbye
+  # https://github.com/ethereum/consensus-specs/blob/v1.2.0-rc.1/specs/phase0/p2p-interface.md#goodbye
   DisconnectionReason* = enum
     # might see other values on the wire!
     ClientShutDown = 1
diff --git a/beacon_chain/nimbus_beacon_node.nim b/beacon_chain/nimbus_beacon_node.nim
index 10aaa34a2..882d02f3c 100644
--- a/beacon_chain/nimbus_beacon_node.nim
+++ b/beacon_chain/nimbus_beacon_node.nim
@@ -126,7 +126,7 @@ template init(T: type RestServerRef,
 
     res.get()
 
-# https://github.com/ethereum/eth2.0-metrics/blob/master/metrics.md#interop-metrics
+# https://github.com/ethereum/beacon-metrics/blob/master/metrics.md#interop-metrics
 declareGauge beacon_slot, "Latest slot of the beacon chain state"
 declareGauge beacon_current_epoch, "Current epoch"
 
diff --git a/beacon_chain/spec/beaconstate.nim b/beacon_chain/spec/beaconstate.nim
index 3fa99f4ef..644ad106f 100644
--- a/beacon_chain/spec/beaconstate.nim
+++ b/beacon_chain/spec/beaconstate.nim
@@ -512,7 +512,7 @@ proc is_valid_indexed_attestation*(
 # Attestation validation
 # ------------------------------------------------------------------------------------------
 # https://github.com/ethereum/consensus-specs/blob/v1.2.0-rc.1/specs/phase0/beacon-chain.md#attestations
-# https://github.com/ethereum/consensus-specs/blob/v1.1.10/specs/phase0/p2p-interface.md#beacon_attestation_subnet_id
+# https://github.com/ethereum/consensus-specs/blob/v1.2.0-rc.1/specs/phase0/p2p-interface.md#beacon_attestation_subnet_id
 
 func check_attestation_slot_target*(data: AttestationData): Result[Slot, cstring] =
   if not (data.target.epoch == epoch(data.slot)):
diff --git a/beacon_chain/spec/digest.nim b/beacon_chain/spec/digest.nim
index 1d2bcbffa..3629b82b9 100644
--- a/beacon_chain/spec/digest.nim
+++ b/beacon_chain/spec/digest.nim
@@ -126,5 +126,5 @@ proc readValue*(r: var JsonReader, a: var Eth2Digest) {.raises: [Defect, IOError
 func toGaugeValue*(hash: Eth2Digest): int64 =
   # Only the last 8 bytes are taken into consideration in accordance
   # to the ETH2 metrics spec:
-  # https://github.com/ethereum/eth2.0-metrics/blob/6a79914cb31f7d54858c7dd57eee75b6162ec737/metrics.md#interop-metrics
+  # https://github.com/ethereum/beacon-metrics/blob/6a79914cb31f7d54858c7dd57eee75b6162ec737/metrics.md#interop-metrics
   cast[int64](uint64.fromBytesLE(hash.data.toOpenArray(24, 31)))
diff --git a/beacon_chain/spec/eth2_apis/rest_remote_signer_calls.nim b/beacon_chain/spec/eth2_apis/rest_remote_signer_calls.nim
index 576cc68bb..da1306860 100644
--- a/beacon_chain/spec/eth2_apis/rest_remote_signer_calls.nim
+++ b/beacon_chain/spec/eth2_apis/rest_remote_signer_calls.nim
@@ -1,4 +1,4 @@
-# Copyright (c) 2018-2021 Status Research & Development GmbH
+# Copyright (c) 2018-2022 Status Research & Development GmbH
 # Licensed and distributed under either of
 #   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
 #   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
@@ -9,7 +9,6 @@
 import
   std/strutils, chronicles, metrics,
   chronos, chronos/apps/http/httpclient, presto, presto/client,
-  nimcrypto/utils as ncrutils,
   serialization, json_serialization,
   json_serialization/std/[options, net, sets],
   stew/[results, base10, byteutils],
diff --git a/beacon_chain/spec/keystore.nim b/beacon_chain/spec/keystore.nim
index dcdd9ef87..46a8e80e6 100644
--- a/beacon_chain/spec/keystore.nim
+++ b/beacon_chain/spec/keystore.nim
@@ -29,7 +29,7 @@ import nimcrypto/utils as ncrutils
 export
   results, burnMem, writeValue, readValue
 
-{.localPassc: "-fno-lto".} # no LTO for crypto
+{.localPassC: "-fno-lto".} # no LTO for crypto
 
 type
   KeystoreMode* = enum
diff --git a/beacon_chain/spec/network.nim b/beacon_chain/spec/network.nim
index 52328e660..206dd73f5 100644
--- a/beacon_chain/spec/network.nim
+++ b/beacon_chain/spec/network.nim
@@ -84,13 +84,13 @@ func getAttestationTopic*(forkDigest: ForkDigest,
   ## For subscribing and unsubscribing to/from a subnet.
   eth2Prefix(forkDigest) & "beacon_attestation_" & $(subnetId) & "/ssz_snappy"
 
-# https://github.com/ethereum/consensus-specs/blob/v1.1.10/specs/altair/p2p-interface.md#topics-and-messages
+# https://github.com/ethereum/consensus-specs/blob/v1.2.0-rc.1/specs/altair/p2p-interface.md#topics-and-messages
 func getSyncCommitteeTopic*(forkDigest: ForkDigest,
                             subcommitteeIdx: SyncSubcommitteeIndex): string =
   ## For subscribing and unsubscribing to/from a subnet.
   eth2Prefix(forkDigest) & "sync_committee_" & $subcommitteeIdx & "/ssz_snappy"
 
-# https://github.com/ethereum/consensus-specs/blob/v1.1.10/specs/altair/p2p-interface.md#topics-and-messages
+# https://github.com/ethereum/consensus-specs/blob/v1.2.0-rc.1/specs/altair/p2p-interface.md#topics-and-messages
 func getSyncCommitteeContributionAndProofTopic*(forkDigest: ForkDigest): string =
   ## For subscribing and unsubscribing to/from a subnet.
   eth2Prefix(forkDigest) & "sync_committee_contribution_and_proof/ssz_snappy"
diff --git a/beacon_chain/spec/state_transition_epoch.nim b/beacon_chain/spec/state_transition_epoch.nim
index 593eaf860..64259f854 100644
--- a/beacon_chain/spec/state_transition_epoch.nim
+++ b/beacon_chain/spec/state_transition_epoch.nim
@@ -1038,23 +1038,23 @@ func process_inactivity_updates*(
 proc process_epoch*(
     cfg: RuntimeConfig, state: var phase0.BeaconState, flags: UpdateFlags,
     cache: var StateCache, info: var phase0.EpochInfo): Result[void, cstring] =
-  let currentEpoch = get_current_epoch(state)
+  let current_epoch = get_current_epoch(state)
   trace "process_epoch",
-    current_epoch = currentEpoch
+    current_epoch
   init(info, state)
   info.process_attestations(state, cache)
 
   process_justification_and_finalization(state, info.balances, flags)
 
   # state.slot hasn't been incremented yet.
-  if verifyFinalization in flags and currentEpoch >= 2:
-    doAssert state.current_justified_checkpoint.epoch + 2 >= currentEpoch
+  if verifyFinalization in flags and current_epoch >= 2:
+    doAssert state.current_justified_checkpoint.epoch + 2 >= current_epoch
 
-  if verifyFinalization in flags and currentEpoch >= 3:
+  if verifyFinalization in flags and current_epoch >= 3:
     # Rule 2/3/4 finalization results in the most pessimal case. The other
     # three finalization rules finalize more quickly as long as the any of
     # the finalization rules triggered.
-    doAssert state.finalized_checkpoint.epoch + 3 >= currentEpoch
+    doAssert state.finalized_checkpoint.epoch + 3 >= current_epoch
 
   process_rewards_and_penalties(state, info)
   ? process_registry_updates(cfg, state, cache)
@@ -1115,7 +1115,7 @@ proc process_epoch*(
 
   process_inactivity_updates(cfg, state, info)  # [New in Altair]
 
-  # https://github.com/ethereum/consensus-specs/blob/v1.1.1/specs/phase0/beacon-chain.md#rewards-and-penalties-1
+  # https://github.com/ethereum/consensus-specs/blob/v1.2.0-rc.1/specs/phase0/beacon-chain.md#process_rewards_and_penalties
   process_rewards_and_penalties(cfg, state, info)
 
   # https://github.com/ethereum/consensus-specs/blob/v1.2.0-rc.1/specs/phase0/beacon-chain.md#registry-updates