Merge branch 'unstable' into deneb-free-blobs

# Conflicts:
#	.github/workflows/docker.yml
#	.github/workflows/local-testnet.yml
#	.github/workflows/test-suite.yml
#	Cargo.lock
#	Cargo.toml
#	beacon_node/beacon_chain/src/beacon_chain.rs
#	beacon_node/beacon_chain/src/builder.rs
#	beacon_node/beacon_chain/src/test_utils.rs
#	beacon_node/execution_layer/src/engine_api/json_structures.rs
#	beacon_node/network/src/beacon_processor/mod.rs
#	beacon_node/network/src/beacon_processor/worker/gossip_methods.rs
#	beacon_node/network/src/sync/backfill_sync/mod.rs
#	beacon_node/store/src/config.rs
#	beacon_node/store/src/hot_cold_store.rs
#	common/eth2_network_config/Cargo.toml
#	consensus/ssz/src/decode/impls.rs
#	consensus/ssz_derive/src/lib.rs
#	consensus/ssz_derive/tests/tests.rs
#	consensus/ssz_types/src/serde_utils/mod.rs
#	consensus/tree_hash/src/impls.rs
#	consensus/tree_hash/src/lib.rs
#	consensus/types/Cargo.toml
#	consensus/types/src/beacon_state.rs
#	consensus/types/src/chain_spec.rs
#	consensus/types/src/eth_spec.rs
#	consensus/types/src/fork_name.rs
#	lcli/Cargo.toml
#	lcli/src/main.rs
#	lcli/src/new_testnet.rs
#	scripts/local_testnet/el_bootnode.sh
#	scripts/local_testnet/genesis.json
#	scripts/local_testnet/geth.sh
#	scripts/local_testnet/setup.sh
#	scripts/local_testnet/start_local_testnet.sh
#	scripts/local_testnet/vars.env
#	scripts/tests/doppelganger_protection.sh
#	scripts/tests/genesis.json
#	scripts/tests/vars.env
#	testing/ef_tests/Cargo.toml
#	validator_client/src/block_service.rs

beacon_node/beacon_chain/src/builder.rs

@@ -8,7 +8,7 @@ use crate::fork_revert::{reset_fork_choice_to_finalization, revert_to_fork_bound
 use crate::head_tracker::HeadTracker;
 use crate::migrate::{BackgroundMigrator, MigratorConfig};
 use crate::persisted_beacon_chain::PersistedBeaconChain;
-use crate::shuffling_cache::ShufflingCache;
+use crate::shuffling_cache::{BlockShufflingIds, ShufflingCache};
 use crate::snapshot_cache::{SnapshotCache, DEFAULT_SNAPSHOT_CACHE_SIZE};
 use crate::timeout_rw_lock::TimeoutRwLock;
 use crate::validator_monitor::ValidatorMonitor;
@@ -710,6 +710,8 @@ where
             )?;
         }
 
+        let head_shuffling_ids = BlockShufflingIds::try_from_head(head_block_root, &head_state)?;
+
         let mut head_snapshot = BeaconSnapshot {
             beacon_block_root: head_block_root,
             beacon_block: Arc::new(head_block),
@@ -791,6 +793,29 @@ where
         let canonical_head = CanonicalHead::new(fork_choice, Arc::new(head_snapshot));
         let shuffling_cache_size = self.chain_config.shuffling_cache_size;
 
+        // Calculate the weak subjectivity point in which to backfill blocks to.
+        let genesis_backfill_slot = if self.chain_config.genesis_backfill {
+            Slot::new(0)
+        } else {
+            let backfill_epoch_range = (self.spec.min_validator_withdrawability_delay
+                + self.spec.churn_limit_quotient)
+                .as_u64()
+                / 2;
+            match slot_clock.now() {
+                Some(current_slot) => {
+                    let genesis_backfill_epoch = current_slot
+                        .epoch(TEthSpec::slots_per_epoch())
+                        .saturating_sub(backfill_epoch_range);
+                    genesis_backfill_epoch.start_slot(TEthSpec::slots_per_epoch())
+                }
+                None => {
+                    // The slot clock cannot derive the current slot. We therefore assume we are
+                    // at or prior to genesis and backfill should sync all the way to genesis.
+                    Slot::new(0)
+                }
+            }
+        };
+
         let beacon_chain = BeaconChain {
             spec: self.spec.clone(),
             config: self.chain_config,
@@ -845,7 +870,11 @@ where
                 DEFAULT_SNAPSHOT_CACHE_SIZE,
                 head_for_snapshot_cache,
             )),
-            shuffling_cache: TimeoutRwLock::new(ShufflingCache::new(shuffling_cache_size)),
+            shuffling_cache: TimeoutRwLock::new(ShufflingCache::new(
+                shuffling_cache_size,
+                head_shuffling_ids,
+                log.clone(),
+            )),
             eth1_finalization_cache: TimeoutRwLock::new(Eth1FinalizationCache::new(log.clone())),
             beacon_proposer_cache: <_>::default(),
             block_times_cache: <_>::default(),
@@ -860,6 +889,7 @@ where
             graffiti: self.graffiti,
             slasher: self.slasher.clone(),
             validator_monitor: RwLock::new(validator_monitor),
+            genesis_backfill_slot,
             //TODO(sean) should we move kzg solely to the da checker?
             data_availability_checker: DataAvailabilityChecker::new(
                 slot_clock,
@@ -1036,7 +1066,7 @@ mod test {
     use super::*;
     use crate::test_utils::EphemeralHarnessType;
     use crate::validator_monitor::DEFAULT_INDIVIDUAL_TRACKING_THRESHOLD;
-    use eth2_hashing::hash;
+    use ethereum_hashing::hash;
     use genesis::{
         generate_deterministic_keypairs, interop_genesis_state, DEFAULT_ETH1_BLOCK_HASH,
     };