Feature gate withdrawals (#3684)

* start feature gating

* feature gate withdrawals

beacon_node/Cargo.toml

@@ -13,6 +13,8 @@ node_test_rig = { path = "../testing/node_test_rig" }
 
 [features]
 write_ssz_files = ["beacon_chain/write_ssz_files"]  # Writes debugging .ssz files to /tmp during block processing.
+withdrawals = ["beacon_chain/withdrawals", "types/withdrawals", "store/withdrawals", "execution_layer/withdrawals"]
+withdrawals-processing = ["beacon_chain/withdrawals-processing", "store/withdrawals-processing", "execution_layer/withdrawals-processing"]
 
 [dependencies]
 eth2_config = { path = "../common/eth2_config" }

beacon_node/beacon_chain/Cargo.toml

@@ -10,6 +10,8 @@ default = ["participation_metrics"]
 write_ssz_files = []  # Writes debugging .ssz files to /tmp during block processing.
 participation_metrics = []  # Exposes validator participation metrics to Prometheus.
 fork_from_env = [] # Initialise the harness chain spec from the FORK_NAME env variable
+withdrawals = ["state_processing/withdrawals", "types/withdrawals", "store/withdrawals", "execution_layer/withdrawals"]
+withdrawals-processing = ["state_processing/withdrawals-processing", "store/withdrawals-processing", "execution_layer/withdrawals-processing"]
 
 [dev-dependencies]
 maplit = "1.0.2"

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -4117,6 +4117,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                     .get_suggested_fee_recipient(proposer as u64)
                     .await,
                 //FIXME(sean)
+                #[cfg(feature = "withdrawals")]
                 withdrawals: vec![],
             }),
         };

beacon_node/execution_layer/Cargo.toml

@@ -4,6 +4,9 @@ version = "0.1.0"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[features]
+withdrawals = ["state_processing/withdrawals", "types/withdrawals"]
+withdrawals-processing = ["state_processing/withdrawals-processing"]
 
 [dependencies]
 types = { path = "../../consensus/types"}

beacon_node/execution_layer/src/engine_api.rs

@@ -155,6 +155,7 @@ pub struct ExecutionBlockWithTransactions<T: EthSpec> {
     #[serde(rename = "hash")]
     pub block_hash: ExecutionBlockHash,
     pub transactions: Vec<Transaction>,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     pub withdrawals: Vec<Withdrawal>,
 }
@@ -204,6 +205,7 @@ impl<T: EthSpec> From<ExecutionPayload<T>> for ExecutionBlockWithTransactions<T>
                         .map(|tx| Transaction::decode(&Rlp::new(tx)))
                         .collect::<Result<Vec<_>, _>>()
                         .unwrap_or_else(|_| Vec::new()),
+                    #[cfg(feature = "withdrawals")]
                     withdrawals: block.withdrawals.into(),
                 })
             }
@@ -229,6 +231,7 @@ impl<T: EthSpec> From<ExecutionPayload<T>> for ExecutionBlockWithTransactions<T>
                         .map(|tx| Transaction::decode(&Rlp::new(tx)))
                         .collect::<Result<Vec<_>, _>>()
                         .unwrap_or_else(|_| Vec::new()),
+                    #[cfg(feature = "withdrawals")]
                     withdrawals: block.withdrawals.into(),
                 })
             }
@@ -236,17 +239,6 @@ impl<T: EthSpec> From<ExecutionPayload<T>> for ExecutionBlockWithTransactions<T>
     }
 }
 
-/*
-impl<T: EthSpec> From<ExecutionBlockWithTransactions<T>> for ExecutionPayload<T> {
-    fn from(block: ExecutionBlockWithTransactions<T>) -> Self {
-        map_execution_block_with_transactions!(block, |inner, cons| {
-            let block = inner.into();
-            cons(block)
-        })
-    }
-}
- */
-
 #[superstruct(
     variants(V1, V2),
     variant_attributes(derive(Clone, Debug, PartialEq),),
@@ -261,6 +253,7 @@ pub struct PayloadAttributes {
     pub prev_randao: Hash256,
     #[superstruct(getter(copy))]
     pub suggested_fee_recipient: Address,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(V2))]
     pub withdrawals: Vec<Withdrawal>,
 }

beacon_node/execution_layer/src/engine_api/json_structures.rs

@@ -99,6 +99,7 @@ pub struct JsonExecutionPayloadHeader<T: EthSpec> {
     pub excess_blobs: u64,
     pub block_hash: ExecutionBlockHash,
     pub transactions_root: Hash256,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(V2, V3))]
     pub withdrawals_root: Hash256,
 }
@@ -137,6 +138,7 @@ impl<T: EthSpec> From<JsonExecutionPayloadHeader<T>> for ExecutionPayloadHeader<
                 base_fee_per_gas: v2.base_fee_per_gas,
                 block_hash: v2.block_hash,
                 transactions_root: v2.transactions_root,
+                #[cfg(feature = "withdrawals")]
                 withdrawals_root: v2.withdrawals_root,
             }),
             JsonExecutionPayloadHeader::V3(v3) => Self::Eip4844(ExecutionPayloadHeaderEip4844 {
@@ -155,6 +157,7 @@ impl<T: EthSpec> From<JsonExecutionPayloadHeader<T>> for ExecutionPayloadHeader<
                 excess_blobs: v3.excess_blobs,
                 block_hash: v3.block_hash,
                 transactions_root: v3.transactions_root,
+                #[cfg(feature = "withdrawals")]
                 withdrawals_root: v3.withdrawals_root,
             }),
         }
@@ -195,6 +198,7 @@ impl<T: EthSpec> From<ExecutionPayloadHeader<T>> for JsonExecutionPayloadHeader<
                 base_fee_per_gas: capella.base_fee_per_gas,
                 block_hash: capella.block_hash,
                 transactions_root: capella.transactions_root,
+                #[cfg(feature = "withdrawals")]
                 withdrawals_root: capella.withdrawals_root,
             }),
             ExecutionPayloadHeader::Eip4844(eip4844) => Self::V3(JsonExecutionPayloadHeaderV3 {
@@ -213,6 +217,7 @@ impl<T: EthSpec> From<ExecutionPayloadHeader<T>> for JsonExecutionPayloadHeader<
                 excess_blobs: eip4844.excess_blobs,
                 block_hash: eip4844.block_hash,
                 transactions_root: eip4844.transactions_root,
+                #[cfg(feature = "withdrawals")]
                 withdrawals_root: eip4844.withdrawals_root,
             }),
         }
@@ -258,6 +263,7 @@ pub struct JsonExecutionPayload<T: EthSpec> {
     #[serde(with = "ssz_types::serde_utils::list_of_hex_var_list")]
     pub transactions:
         VariableList<Transaction<T::MaxBytesPerTransaction>, T::MaxTransactionsPerPayload>,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(V2, V3))]
     pub withdrawals: VariableList<Withdrawal, T::MaxWithdrawalsPerPayload>,
 }
@@ -296,6 +302,7 @@ impl<T: EthSpec> From<JsonExecutionPayload<T>> for ExecutionPayload<T> {
                 base_fee_per_gas: v2.base_fee_per_gas,
                 block_hash: v2.block_hash,
                 transactions: v2.transactions,
+                #[cfg(feature = "withdrawals")]
                 withdrawals: v2.withdrawals,
             }),
             JsonExecutionPayload::V3(v3) => Self::Eip4844(ExecutionPayloadEip4844 {
@@ -314,6 +321,7 @@ impl<T: EthSpec> From<JsonExecutionPayload<T>> for ExecutionPayload<T> {
                 excess_blobs: v3.excess_blobs,
                 block_hash: v3.block_hash,
                 transactions: v3.transactions,
+                #[cfg(feature = "withdrawals")]
                 withdrawals: v3.withdrawals,
             }),
         }
@@ -354,6 +362,7 @@ impl<T: EthSpec> From<ExecutionPayload<T>> for JsonExecutionPayload<T> {
                 base_fee_per_gas: capella.base_fee_per_gas,
                 block_hash: capella.block_hash,
                 transactions: capella.transactions,
+                #[cfg(feature = "withdrawals")]
                 withdrawals: capella.withdrawals,
             }),
             ExecutionPayload::Eip4844(eip4844) => Self::V3(JsonExecutionPayloadV3 {
@@ -372,6 +381,7 @@ impl<T: EthSpec> From<ExecutionPayload<T>> for JsonExecutionPayload<T> {
                 excess_blobs: eip4844.excess_blobs,
                 block_hash: eip4844.block_hash,
                 transactions: eip4844.transactions,
+                #[cfg(feature = "withdrawals")]
                 withdrawals: eip4844.withdrawals,
             }),
         }
@@ -425,6 +435,7 @@ pub struct JsonPayloadAttributes {
     pub timestamp: u64,
     pub prev_randao: Hash256,
     pub suggested_fee_recipient: Address,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(V2))]
     pub withdrawals: Vec<JsonWithdrawal>,
 }
@@ -441,6 +452,7 @@ impl From<PayloadAttributes> for JsonPayloadAttributes {
                 timestamp: pa.timestamp,
                 prev_randao: pa.prev_randao,
                 suggested_fee_recipient: pa.suggested_fee_recipient,
+                #[cfg(feature = "withdrawals")]
                 withdrawals: pa.withdrawals.into_iter().map(Into::into).collect(),
             }),
         }
@@ -459,6 +471,7 @@ impl From<JsonPayloadAttributes> for PayloadAttributes {
                 timestamp: jpa.timestamp,
                 prev_randao: jpa.prev_randao,
                 suggested_fee_recipient: jpa.suggested_fee_recipient,
+                #[cfg(feature = "withdrawals")]
                 withdrawals: jpa.withdrawals.into_iter().map(Into::into).collect(),
             }),
         }

beacon_node/execution_layer/src/lib.rs

@@ -1499,6 +1499,7 @@ impl<T: EthSpec> ExecutionLayer<T> {
                 })
             }
             ExecutionBlockWithTransactions::Capella(capella_block) => {
+                #[cfg(feature = "withdrawals")]
                 let withdrawals = VariableList::new(capella_block.withdrawals.clone())
                     .map_err(ApiError::DeserializeWithdrawals)?;
 
@@ -1517,10 +1518,12 @@ impl<T: EthSpec> ExecutionLayer<T> {
                     base_fee_per_gas: capella_block.base_fee_per_gas,
                     block_hash: capella_block.block_hash,
                     transactions,
+                    #[cfg(feature = "withdrawals")]
                     withdrawals,
                 })
             }
             ExecutionBlockWithTransactions::Eip4844(eip4844_block) => {
+                #[cfg(feature = "withdrawals")]
                 let withdrawals = VariableList::new(eip4844_block.withdrawals.clone())
                     .map_err(ApiError::DeserializeWithdrawals)?;
 
@@ -1540,6 +1543,7 @@ impl<T: EthSpec> ExecutionLayer<T> {
                     excess_blobs: eip4844_block.excess_blobs,
                     block_hash: eip4844_block.block_hash,
                     transactions,
+                    #[cfg(feature = "withdrawals")]
                     withdrawals,
                 })
             }

beacon_node/execution_layer/src/test_utils/execution_block_generator.rs

@@ -403,6 +403,7 @@ impl<T: EthSpec> ExecutionBlockGenerator<T> {
                             base_fee_per_gas: Uint256::one(),
                             block_hash: ExecutionBlockHash::zero(),
                             transactions: vec![].into(),
+                            #[cfg(feature = "withdrawals")]
                             withdrawals: pa
                                 .withdrawals
                                 .iter()

beacon_node/execution_layer/src/test_utils/mock_execution_layer.rs

@@ -113,6 +113,7 @@ impl<T: EthSpec> MockExecutionLayer<T> {
                         prev_randao,
                         suggested_fee_recipient: Address::repeat_byte(42),
                         // FIXME: think about adding withdrawals here..
+                        #[cfg(feature = "withdrawals")]
                         withdrawals: vec![],
                     })
                 }

beacon_node/store/Cargo.toml

@@ -26,3 +26,7 @@ lru = "0.7.1"
 sloggers = { version = "2.1.1", features = ["json"] }
 directory = { path = "../../common/directory" }
 strum = { version = "0.24.0", features = ["derive"] }
+
+[features]
+withdrawals = ["state_processing/withdrawals", "types/withdrawals"]
+withdrawals-processing = ["state_processing/withdrawals-processing"]

beacon_node/store/src/partial_beacon_state.rs

@@ -105,10 +105,13 @@ where
     pub latest_execution_payload_header: ExecutionPayloadHeaderEip4844<T>,
 
     // Withdrawals
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     pub withdrawal_queue: VariableList<Withdrawal, T::WithdrawalQueueLimit>,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     pub next_withdrawal_index: u64,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     pub next_partial_withdrawal_validator_index: u64,
 }
@@ -199,6 +202,7 @@ impl<T: EthSpec> PartialBeaconState<T> {
                     latest_execution_payload_header
                 ]
             ),
+            #[cfg(feature = "withdrawals")]
             BeaconState::Capella(s) => impl_from_state_forgetful!(
                 s,
                 outer,
@@ -216,6 +220,22 @@ impl<T: EthSpec> PartialBeaconState<T> {
                     next_partial_withdrawal_validator_index
                 ]
             ),
+            #[cfg(not(feature = "withdrawals"))]
+            BeaconState::Capella(s) => impl_from_state_forgetful!(
+                s,
+                outer,
+                Capella,
+                PartialBeaconStateCapella,
+                [
+                    previous_epoch_participation,
+                    current_epoch_participation,
+                    current_sync_committee,
+                    next_sync_committee,
+                    inactivity_scores,
+                    latest_execution_payload_header
+                ]
+            ),
+            #[cfg(feature = "withdrawals")]
             BeaconState::Eip4844(s) => impl_from_state_forgetful!(
                 s,
                 outer,
@@ -233,6 +253,21 @@ impl<T: EthSpec> PartialBeaconState<T> {
                     next_partial_withdrawal_validator_index
                 ]
             ),
+            #[cfg(not(feature = "withdrawals"))]
+            BeaconState::Eip4844(s) => impl_from_state_forgetful!(
+                s,
+                outer,
+                Eip4844,
+                PartialBeaconStateEip4844,
+                [
+                    previous_epoch_participation,
+                    current_epoch_participation,
+                    current_sync_committee,
+                    next_sync_committee,
+                    inactivity_scores,
+                    latest_execution_payload_header
+                ]
+            ),
         }
     }
 
@@ -420,6 +455,7 @@ impl<E: EthSpec> TryInto<BeaconState<E>> for PartialBeaconState<E> {
                     latest_execution_payload_header
                 ]
             ),
+            #[cfg(feature = "withdrawals")]
             PartialBeaconState::Capella(inner) => impl_try_into_beacon_state!(
                 inner,
                 Capella,
@@ -436,6 +472,21 @@ impl<E: EthSpec> TryInto<BeaconState<E>> for PartialBeaconState<E> {
                     next_partial_withdrawal_validator_index
                 ]
             ),
+            #[cfg(not(feature = "withdrawals"))]
+            PartialBeaconState::Capella(inner) => impl_try_into_beacon_state!(
+                inner,
+                Capella,
+                BeaconStateCapella,
+                [
+                    previous_epoch_participation,
+                    current_epoch_participation,
+                    current_sync_committee,
+                    next_sync_committee,
+                    inactivity_scores,
+                    latest_execution_payload_header
+                ]
+            ),
+            #[cfg(feature = "withdrawals")]
             PartialBeaconState::Eip4844(inner) => impl_try_into_beacon_state!(
                 inner,
                 Eip4844,
@@ -452,6 +503,20 @@ impl<E: EthSpec> TryInto<BeaconState<E>> for PartialBeaconState<E> {
                     next_partial_withdrawal_validator_index
                 ]
             ),
+            #[cfg(not(feature = "withdrawals"))]
+            PartialBeaconState::Eip4844(inner) => impl_try_into_beacon_state!(
+                inner,
+                Eip4844,
+                BeaconStateEip4844,
+                [
+                    previous_epoch_participation,
+                    current_epoch_participation,
+                    current_sync_committee,
+                    next_sync_committee,
+                    inactivity_scores,
+                    latest_execution_payload_header
+                ]
+            ),
         };
         Ok(state)
     }

consensus/state_processing/Cargo.toml

@@ -43,3 +43,5 @@ arbitrary-fuzz = [
   "eth2_ssz_types/arbitrary",
   "tree_hash/arbitrary",
 ]
+withdrawals = ["types/withdrawals"]
+withdrawals-processing = []

consensus/state_processing/src/common/mod.rs

@@ -15,6 +15,7 @@ pub use get_attesting_indices::{get_attesting_indices, get_attesting_indices_fro
 pub use get_indexed_attestation::get_indexed_attestation;
 pub use initiate_validator_exit::initiate_validator_exit;
 pub use slash_validator::slash_validator;
+#[cfg(feature = "withdrawals")]
 pub use withdraw_balance::withdraw_balance;
 
 use safe_arith::SafeArith;

consensus/state_processing/src/common/withdraw_balance.rs

@@ -2,6 +2,7 @@ use crate::common::decrease_balance;
 use safe_arith::SafeArith;
 use types::{BeaconStateError as Error, *};
 
+#[cfg(feature = "withdrawals")]
 pub fn withdraw_balance<T: EthSpec>(
     state: &mut BeaconState<T>,
     validator_index: usize,

consensus/state_processing/src/per_epoch_processing/capella.rs

@@ -5,11 +5,15 @@ use crate::per_epoch_processing::{
     historical_roots_update::process_historical_roots_update,
     resets::{process_eth1_data_reset, process_randao_mixes_reset, process_slashings_reset},
 };
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 pub use full_withdrawals::process_full_withdrawals;
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 pub use partial_withdrawals::process_partial_withdrawals;
 use types::{BeaconState, ChainSpec, EthSpec, RelativeEpoch};
 
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 pub mod full_withdrawals;
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 pub mod partial_withdrawals;
 
 pub fn process_epoch<T: EthSpec>(
@@ -66,8 +70,10 @@ pub fn process_epoch<T: EthSpec>(
     altair::process_sync_committee_updates(state, spec)?;
 
     // Withdrawals
+    #[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
     process_full_withdrawals(state, spec)?;
 
+    #[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
     process_partial_withdrawals(state, spec)?;
 
     // Rotate the epoch caches to suit the epoch transition.

consensus/state_processing/src/per_epoch_processing/capella/full_withdrawals.rs

@@ -1,7 +1,9 @@
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 use crate::common::withdraw_balance;
 use crate::EpochProcessingError;
 use types::{beacon_state::BeaconState, eth_spec::EthSpec, ChainSpec};
 
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 pub fn process_full_withdrawals<T: EthSpec>(
     state: &mut BeaconState<T>,
     spec: &ChainSpec,

consensus/state_processing/src/per_epoch_processing/capella/partial_withdrawals.rs

@@ -1,8 +1,10 @@
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 use crate::common::withdraw_balance;
 use crate::EpochProcessingError;
 use safe_arith::SafeArith;
 use types::{beacon_state::BeaconState, eth_spec::EthSpec, ChainSpec};
 
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 pub fn process_partial_withdrawals<T: EthSpec>(
     state: &mut BeaconState<T>,
     spec: &ChainSpec,

consensus/state_processing/src/upgrade/capella.rs

@@ -57,8 +57,11 @@ pub fn upgrade_to_capella<E: EthSpec>(
         // Execution
         latest_execution_payload_header: pre.latest_execution_payload_header.upgrade_to_capella(),
         // Withdrawals
+        #[cfg(feature = "withdrawals")]
         withdrawal_queue: VariableList::empty(),
+        #[cfg(feature = "withdrawals")]
         next_withdrawal_index: 0,
+        #[cfg(feature = "withdrawals")]
         next_partial_withdrawal_validator_index: 0,
         // Caches
         total_active_balance: pre.total_active_balance,

consensus/state_processing/src/upgrade/eip4844.rs

@@ -9,6 +9,14 @@ pub fn upgrade_to_eip4844<E: EthSpec>(
     let epoch = pre_state.current_epoch();
     let pre = pre_state.as_capella_mut()?;
 
+    // FIXME(sean) This is a hack to let us participate in testnets where capella doesn't exist.
+    // if we are disabling withdrawals, assume we should fork off of bellatrix.
+    let previous_fork_version = if cfg!(feature ="withdrawals") {
+        pre.fork.current_version
+    } else {
+        spec.bellatrix_fork_epoch
+    };
+
     // Where possible, use something like `mem::take` to move fields from behind the &mut
     // reference. For other fields that don't have a good default value, use `clone`.
     //
@@ -20,7 +28,7 @@ pub fn upgrade_to_eip4844<E: EthSpec>(
         genesis_validators_root: pre.genesis_validators_root,
         slot: pre.slot,
         fork: Fork {
-            previous_version: pre.fork.current_version,
+            previous_version: previous_fork_version,
             current_version: spec.eip4844_fork_version,
             epoch,
         },
@@ -56,8 +64,11 @@ pub fn upgrade_to_eip4844<E: EthSpec>(
         // Execution
         latest_execution_payload_header: pre.latest_execution_payload_header.upgrade_to_eip4844(),
         // Withdrawals
+        #[cfg(feature = "withdrawals")]
         withdrawal_queue: mem::take(&mut pre.withdrawal_queue),
+        #[cfg(feature = "withdrawals")]
         next_withdrawal_index: pre.next_withdrawal_index,
+        #[cfg(feature = "withdrawals")]
         next_partial_withdrawal_validator_index: pre.next_partial_withdrawal_validator_index,
         // Caches
         total_active_balance: pre.total_active_balance,

consensus/types/Cargo.toml

@@ -71,3 +71,4 @@ arbitrary-fuzz = [
   "swap_or_not_shuffle/arbitrary",
   "tree_hash/arbitrary",
 ]
+withdrawals = []

consensus/types/src/beacon_state.rs

@@ -295,10 +295,13 @@ where
     pub latest_execution_payload_header: ExecutionPayloadHeaderEip4844<T>,
 
     // Withdrawals
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     pub withdrawal_queue: VariableList<Withdrawal, T::WithdrawalQueueLimit>,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     pub next_withdrawal_index: u64,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     pub next_partial_withdrawal_validator_index: u64,
 

consensus/types/src/execution_payload.rs

@@ -80,6 +80,7 @@ pub struct ExecutionPayload<T: EthSpec> {
     pub block_hash: ExecutionBlockHash,
     #[serde(with = "ssz_types::serde_utils::list_of_hex_var_list")]
     pub transactions: Transactions<T>,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     pub withdrawals: VariableList<Withdrawal, T::MaxWithdrawalsPerPayload>,
 }

consensus/types/src/execution_payload_header.rs

@@ -74,6 +74,7 @@ pub struct ExecutionPayloadHeader<T: EthSpec> {
     pub block_hash: ExecutionBlockHash,
     #[superstruct(getter(copy))]
     pub transactions_root: Hash256,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     #[superstruct(getter(copy))]
     pub withdrawals_root: Hash256,
@@ -104,6 +105,7 @@ impl<'a, T: EthSpec> ExecutionPayloadHeaderRef<'a, T> {
 
 impl<T: EthSpec> ExecutionPayloadHeaderMerge<T> {
     pub fn upgrade_to_capella(&self) -> ExecutionPayloadHeaderCapella<T> {
+        #[cfg(feature = "withdrawals")]
         // TODO: if this is correct we should calculate and hardcode this..
         let empty_withdrawals_root =
             VariableList::<Withdrawal, T::MaxWithdrawalsPerPayload>::empty().tree_hash_root();
@@ -122,6 +124,7 @@ impl<T: EthSpec> ExecutionPayloadHeaderMerge<T> {
             base_fee_per_gas: self.base_fee_per_gas,
             block_hash: self.block_hash,
             transactions_root: self.transactions_root,
+            #[cfg(feature = "withdrawals")]
             // FIXME: the spec doesn't seem to define what to do here..
             withdrawals_root: empty_withdrawals_root,
         }
@@ -147,6 +150,7 @@ impl<T: EthSpec> ExecutionPayloadHeaderCapella<T> {
             excess_blobs: 0,
             block_hash: self.block_hash,
             transactions_root: self.transactions_root,
+            #[cfg(feature = "withdrawals")]
             withdrawals_root: self.withdrawals_root,
         }
     }
@@ -189,6 +193,7 @@ impl<T: EthSpec> From<ExecutionPayloadCapella<T>> for ExecutionPayloadHeaderCape
             base_fee_per_gas: payload.base_fee_per_gas,
             block_hash: payload.block_hash,
             transactions_root: payload.transactions.tree_hash_root(),
+            #[cfg(feature = "withdrawals")]
             withdrawals_root: payload.withdrawals.tree_hash_root(),
         }
     }
@@ -211,6 +216,7 @@ impl<T: EthSpec> From<ExecutionPayloadEip4844<T>> for ExecutionPayloadHeaderEip4
             excess_blobs: payload.excess_blobs,
             block_hash: payload.block_hash,
             transactions_root: payload.transactions.tree_hash_root(),
+            #[cfg(feature = "withdrawals")]
             withdrawals_root: payload.withdrawals.tree_hash_root(),
         }
     }

lighthouse/Cargo.toml

@@ -24,6 +24,10 @@ gnosis = []
 slasher-mdbx = ["slasher/mdbx"]
 # Support slasher LMDB backend.
 slasher-lmdb = ["slasher/lmdb"]
+# Support for inclusion of withdrawals fields in all capella consensus types in all APIs.
+withdrawals = ["types/withdrawals", "beacon_node/withdrawals"]
+# Support for withdrawals consensus processing logic.
+withdrawals-processing = ["beacon_node/withdrawals-processing"]
 
 [dependencies]
 beacon_node = { "path" = "../beacon_node" }