Migrate derivative to educe (#8125)

Fixes #7001.


  Mostly mechanical replacement of `derivative` attributes with `educe` ones.

### **Attribute Syntax Changes**

```rust
// Bounds: = "..." → (...)
#[derivative(Hash(bound = "E: EthSpec"))]
#[educe(Hash(bound(E: EthSpec)))]

// Ignore: = "ignore" → (ignore)
#[derivative(PartialEq = "ignore")]
#[educe(PartialEq(ignore))]

// Default values: value = "..." → expression = ...
#[derivative(Default(value = "ForkName::Base"))]
#[educe(Default(expression = ForkName::Base))]

// Methods: format_with/compare_with = "..." → method(...)
#[derivative(Debug(format_with = "fmt_peer_set_as_len"))]
#[educe(Debug(method(fmt_peer_set_as_len)))]

// Empty bounds: removed entirely, educe can infer appropriate bounds
#[derivative(Default(bound = ""))]
#[educe(Default)]

// Transparent debug: manual implementation (educe doesn't support it)
#[derivative(Debug = "transparent")]
// Replaced with manual Debug impl that delegates to inner field
```

**Note**: Some bounds use strings (`bound("E: EthSpec")`) for superstruct compatibility (`expected ','` errors).


Co-Authored-By: Javier Chávarri <javier.chavarri@gmail.com>

Co-Authored-By: Mac L <mjladson@pm.me>

beacon_node/beacon_chain/Cargo.toml

@@ -18,7 +18,7 @@ test_backfill = []
 alloy-primitives = { workspace = true }
 bitvec = { workspace = true }
 bls = { workspace = true }
-derivative = { workspace = true }
+educe = { workspace = true }
 eth2 = { workspace = true }
 eth2_network_config = { workspace = true }
 ethereum_hashing = { workspace = true }

beacon_node/beacon_chain/src/beacon_fork_choice_store.rs

@@ -5,7 +5,7 @@
 //! reads when fork choice requires the validator balances of the justified state.
 
 use crate::{BeaconSnapshot, metrics};
-use derivative::Derivative;
+use educe::Educe;
 use fork_choice::ForkChoiceStore;
 use proto_array::JustifiedBalances;
 use safe_arith::ArithError;
@@ -127,10 +127,10 @@ impl BalancesCache {
 
 /// Implements `fork_choice::ForkChoiceStore` in order to provide a persistent backing to the
 /// `fork_choice::ForkChoice` struct.
-#[derive(Debug, Derivative)]
-#[derivative(PartialEq(bound = "E: EthSpec, Hot: ItemStore<E>, Cold: ItemStore<E>"))]
+#[derive(Debug, Educe)]
+#[educe(PartialEq(bound(E: EthSpec, Hot: ItemStore<E>, Cold: ItemStore<E>)))]
 pub struct BeaconForkChoiceStore<E: EthSpec, Hot: ItemStore<E>, Cold: ItemStore<E>> {
-    #[derivative(PartialEq = "ignore")]
+    #[educe(PartialEq(ignore))]
     store: Arc<HotColdDB<E, Hot, Cold>>,
     balances_cache: BalancesCache,
     time: Slot,

beacon_node/beacon_chain/src/blob_verification.rs

@@ -1,4 +1,4 @@
-use derivative::Derivative;
+use educe::Educe;
 use slot_clock::SlotClock;
 use std::marker::PhantomData;
 use std::sync::Arc;
@@ -245,8 +245,8 @@ impl<T: BeaconChainTypes, O: ObservationStrategy> GossipVerifiedBlob<T, O> {
 
 /// Wrapper over a `BlobSidecar` for which we have completed kzg verification.
 /// i.e. `verify_blob_kzg_proof(blob, commitment, proof) == true`.
-#[derive(Debug, Derivative, Clone, Encode, Decode)]
-#[derivative(PartialEq, Eq)]
+#[derive(Debug, Educe, Clone, Encode, Decode)]
+#[educe(PartialEq, Eq)]
 #[ssz(struct_behaviour = "transparent")]
 pub struct KzgVerifiedBlob<E: EthSpec> {
     blob: Arc<BlobSidecar<E>>,

beacon_node/beacon_chain/src/block_verification.rs

@@ -66,7 +66,7 @@ use crate::{
     beacon_chain::{BeaconForkChoice, ForkChoiceError},
     metrics,
 };
-use derivative::Derivative;
+use educe::Educe;
 use eth2::types::{BlockGossip, EventKind};
 use execution_layer::PayloadStatus;
 pub use fork_choice::{AttestationFromBlock, PayloadVerificationStatus};
@@ -689,8 +689,8 @@ pub fn signature_verify_chain_segment<T: BeaconChainTypes>(
 
 /// A wrapper around a `SignedBeaconBlock` that indicates it has been approved for re-gossiping on
 /// the p2p network.
-#[derive(Derivative)]
-#[derivative(Debug(bound = "T: BeaconChainTypes"))]
+#[derive(Educe)]
+#[educe(Debug(bound(T: BeaconChainTypes)))]
 pub struct GossipVerifiedBlock<T: BeaconChainTypes> {
     pub block: Arc<SignedBeaconBlock<T::EthSpec>>,
     pub block_root: Hash256,

beacon_node/beacon_chain/src/block_verification_types.rs

@@ -2,7 +2,7 @@ use crate::data_availability_checker::AvailabilityCheckError;
 pub use crate::data_availability_checker::{AvailableBlock, MaybeAvailableBlock};
 use crate::data_column_verification::{CustodyDataColumn, CustodyDataColumnList};
 use crate::{PayloadVerificationOutcome, get_block_root};
-use derivative::Derivative;
+use educe::Educe;
 use ssz_types::VariableList;
 use state_processing::ConsensusContext;
 use std::fmt::{Debug, Formatter};
@@ -26,8 +26,8 @@ use types::{
 /// Note: We make a distinction over blocks received over gossip because
 /// in a post-deneb world, the blobs corresponding to a given block that are received
 /// over rpc do not contain the proposer signature for dos resistance.
-#[derive(Clone, Derivative)]
-#[derivative(Hash(bound = "E: EthSpec"))]
+#[derive(Clone, Educe)]
+#[educe(Hash(bound(E: EthSpec)))]
 pub struct RpcBlock<E: EthSpec> {
     block_root: Hash256,
     block: RpcBlockInner<E>,
@@ -80,8 +80,8 @@ impl<E: EthSpec> RpcBlock<E> {
 /// Note: This variant is intentionally private because we want to safely construct the
 /// internal variants after applying consistency checks to ensure that the block and blobs
 /// are consistent with respect to each other.
-#[derive(Debug, Clone, Derivative)]
-#[derivative(Hash(bound = "E: EthSpec"))]
+#[derive(Debug, Clone, Educe)]
+#[educe(Hash(bound(E: EthSpec)))]
 enum RpcBlockInner<E: EthSpec> {
     /// Single block lookup response. This should potentially hit the data availability cache.
     Block(Arc<SignedBeaconBlock<E>>),

beacon_node/beacon_chain/src/data_column_verification.rs

@@ -4,7 +4,7 @@ use crate::block_verification::{
 use crate::kzg_utils::{reconstruct_data_columns, validate_data_columns};
 use crate::observed_data_sidecars::{ObservationStrategy, Observe};
 use crate::{BeaconChain, BeaconChainError, BeaconChainTypes, metrics};
-use derivative::Derivative;
+use educe::Educe;
 use fork_choice::ProtoBlock;
 use kzg::{Error as KzgError, Kzg};
 use proto_array::Block;
@@ -296,8 +296,8 @@ impl<T: BeaconChainTypes, O: ObservationStrategy> GossipVerifiedDataColumn<T, O>
 }
 
 /// Wrapper over a `DataColumnSidecar` for which we have completed kzg verification.
-#[derive(Debug, Derivative, Clone, Encode, Decode)]
-#[derivative(PartialEq, Eq)]
+#[derive(Debug, Educe, Clone, Encode, Decode)]
+#[educe(PartialEq, Eq)]
 #[ssz(struct_behaviour = "transparent")]
 pub struct KzgVerifiedDataColumn<E: EthSpec> {
     data: Arc<DataColumnSidecar<E>>,
@@ -353,8 +353,8 @@ pub type CustodyDataColumnList<E> =
     VariableList<CustodyDataColumn<E>, <E as EthSpec>::NumberOfColumns>;
 
 /// Data column that we must custody
-#[derive(Debug, Derivative, Clone, Encode, Decode)]
-#[derivative(PartialEq, Eq, Hash(bound = "E: EthSpec"))]
+#[derive(Debug, Educe, Clone, Encode, Decode)]
+#[educe(PartialEq, Eq, Hash(bound(E: EthSpec)))]
 #[ssz(struct_behaviour = "transparent")]
 pub struct CustodyDataColumn<E: EthSpec> {
     data: Arc<DataColumnSidecar<E>>,
@@ -383,8 +383,8 @@ impl<E: EthSpec> CustodyDataColumn<E> {
 }
 
 /// Data column that we must custody and has completed kzg verification
-#[derive(Debug, Derivative, Clone, Encode, Decode)]
-#[derivative(PartialEq, Eq)]
+#[derive(Debug, Educe, Clone, Encode, Decode)]
+#[educe(PartialEq, Eq)]
 #[ssz(struct_behaviour = "transparent")]
 pub struct KzgVerifiedCustodyDataColumn<E: EthSpec> {
     data: Arc<DataColumnSidecar<E>>,

beacon_node/beacon_chain/src/light_client_finality_update_verification.rs

@@ -1,5 +1,5 @@
 use crate::{BeaconChain, BeaconChainTypes};
-use derivative::Derivative;
+use educe::Educe;
 use slot_clock::SlotClock;
 use std::time::Duration;
 use strum::AsRefStr;
@@ -55,8 +55,8 @@ pub enum Error {
 }
 
 /// Wraps a `LightClientFinalityUpdate` that has been verified for propagation on the gossip network.
-#[derive(Derivative)]
-#[derivative(Clone(bound = "T: BeaconChainTypes"))]
+#[derive(Educe)]
+#[educe(Clone(bound(T: BeaconChainTypes)))]
 pub struct VerifiedLightClientFinalityUpdate<T: BeaconChainTypes> {
     light_client_finality_update: LightClientFinalityUpdate<T::EthSpec>,
     seen_timestamp: Duration,

beacon_node/beacon_chain/src/light_client_optimistic_update_verification.rs

@@ -1,5 +1,5 @@
 use crate::{BeaconChain, BeaconChainTypes};
-use derivative::Derivative;
+use educe::Educe;
 use eth2::types::Hash256;
 use slot_clock::SlotClock;
 use std::time::Duration;
@@ -49,8 +49,8 @@ pub enum Error {
 }
 
 /// Wraps a `LightClientOptimisticUpdate` that has been verified for propagation on the gossip network.
-#[derive(Derivative)]
-#[derivative(Clone(bound = "T: BeaconChainTypes"))]
+#[derive(Educe)]
+#[educe(Clone(bound(T: BeaconChainTypes)))]
 pub struct VerifiedLightClientOptimisticUpdate<T: BeaconChainTypes> {
     light_client_optimistic_update: LightClientOptimisticUpdate<T::EthSpec>,
     pub parent_root: Hash256,

beacon_node/beacon_chain/src/observed_operations.rs

@@ -1,4 +1,4 @@
-use derivative::Derivative;
+use educe::Educe;
 use smallvec::{SmallVec, smallvec};
 use state_processing::{SigVerifiedOp, TransformPersist, VerifyOperation, VerifyOperationAt};
 use std::collections::HashSet;
@@ -14,8 +14,8 @@ pub const SMALL_VEC_SIZE: usize = 8;
 /// Stateful tracker for exit/slashing operations seen on the network.
 ///
 /// Implements the conditions for gossip verification of exits and slashings from the P2P spec.
-#[derive(Debug, Derivative)]
-#[derivative(Default(bound = "T: ObservableOperation<E>, E: EthSpec"))]
+#[derive(Debug, Educe)]
+#[educe(Default(bound(T: ObservableOperation<E>, E: EthSpec)))]
 pub struct ObservedOperations<T: ObservableOperation<E>, E: EthSpec> {
     /// Indices of validators for whom we have already seen an instance of an operation `T`.
     ///
@@ -26,7 +26,7 @@ pub struct ObservedOperations<T: ObservableOperation<E>, E: EthSpec> {
     /// `attestation_1.attester_indices` and `attestation_2.attester_indices`.
     observed_validator_indices: HashSet<u64>,
     /// The name of the current fork. The default will be overwritten on first use.
-    #[derivative(Default(value = "ForkName::Base"))]
+    #[educe(Default(expression = ForkName::Base))]
     current_fork: ForkName,
     _phantom: PhantomData<(T, E)>,
 }

beacon_node/beacon_chain/src/sync_committee_verification.rs

@@ -31,7 +31,7 @@ use crate::{
     BeaconChain, BeaconChainError, BeaconChainTypes, metrics, observed_aggregates::ObserveOutcome,
 };
 use bls::{PublicKeyBytes, verify_signature_sets};
-use derivative::Derivative;
+use educe::Educe;
 use safe_arith::ArithError;
 use slot_clock::SlotClock;
 use ssz_derive::{Decode, Encode};
@@ -261,8 +261,8 @@ impl From<ContributionError> for Error {
 }
 
 /// Wraps a `SignedContributionAndProof` that has been verified for propagation on the gossip network.\
-#[derive(Derivative)]
-#[derivative(Clone(bound = "T: BeaconChainTypes"))]
+#[derive(Educe)]
+#[educe(Clone(bound(T: BeaconChainTypes)))]
 pub struct VerifiedSyncContribution<T: BeaconChainTypes> {
     signed_aggregate: SignedContributionAndProof<T::EthSpec>,
     participant_pubkeys: Vec<PublicKeyBytes>,

beacon_node/network/Cargo.toml

@@ -19,7 +19,7 @@ async-channel = { workspace = true }
 beacon_chain = { workspace = true }
 beacon_processor = { workspace = true }
 delay_map = { workspace = true }
-derivative = { workspace = true }
+educe = { workspace = true }
 ethereum_ssz = { workspace = true }
 execution_layer = { workspace = true }
 fnv = { workspace = true }

beacon_node/network/src/sync/batch.rs

@@ -1,5 +1,5 @@
 use beacon_chain::block_verification_types::RpcBlock;
-use derivative::Derivative;
+use educe::Educe;
 use lighthouse_network::PeerId;
 use lighthouse_network::rpc::methods::BlocksByRangeRequest;
 use lighthouse_network::rpc::methods::DataColumnsByRangeRequest;
@@ -78,8 +78,8 @@ pub enum BatchProcessingResult {
     NonFaultyFailure,
 }
 
-#[derive(Derivative)]
-#[derivative(Debug)]
+#[derive(Educe)]
+#[educe(Debug)]
 /// A segment of a chain.
 pub struct BatchInfo<E: EthSpec, B: BatchConfig, D: Hash> {
     /// Start slot of the batch.
@@ -97,7 +97,7 @@ pub struct BatchInfo<E: EthSpec, B: BatchConfig, D: Hash> {
     /// Whether this batch contains all blocks or all blocks and blobs.
     batch_type: ByRangeRequestType,
     /// Pin the generic
-    #[derivative(Debug = "ignore")]
+    #[educe(Debug(ignore))]
     marker: std::marker::PhantomData<(E, B)>,
 }
 

beacon_node/network/src/sync/block_lookups/single_block_lookup.rs

@@ -5,7 +5,7 @@ use crate::sync::network_context::{
     SyncNetworkContext,
 };
 use beacon_chain::{BeaconChainTypes, BlockProcessStatus};
-use derivative::Derivative;
+use educe::Educe;
 use lighthouse_network::service::api_types::Id;
 use lighthouse_tracing::SPAN_SINGLE_BLOCK_LOOKUP;
 use parking_lot::RwLock;
@@ -57,8 +57,8 @@ pub enum LookupRequestError {
     },
 }
 
-#[derive(Derivative)]
-#[derivative(Debug(bound = "T: BeaconChainTypes"))]
+#[derive(Educe)]
+#[educe(Debug(bound(T: BeaconChainTypes)))]
 pub struct SingleBlockLookup<T: BeaconChainTypes> {
     pub id: Id,
     pub block_request_state: BlockRequestState<T::EthSpec>,
@@ -67,7 +67,7 @@ pub struct SingleBlockLookup<T: BeaconChainTypes> {
     /// the custody request to have an updated view of the peers that claim to have imported the
     /// block associated with this lookup. The peer set of a lookup can change rapidly, and faster
     /// than the lifetime of a custody request.
-    #[derivative(Debug(format_with = "fmt_peer_set_as_len"))]
+    #[educe(Debug(method(fmt_peer_set_as_len)))]
     peers: Arc<RwLock<HashSet<PeerId>>>,
     block_root: Hash256,
     awaiting_parent: Option<Hash256>,
@@ -369,10 +369,10 @@ impl<T: BeaconChainTypes> SingleBlockLookup<T> {
 }
 
 /// The state of the blob request component of a `SingleBlockLookup`.
-#[derive(Derivative)]
-#[derivative(Debug)]
+#[derive(Educe)]
+#[educe(Debug)]
 pub struct BlobRequestState<E: EthSpec> {
-    #[derivative(Debug = "ignore")]
+    #[educe(Debug(ignore))]
     pub block_root: Hash256,
     pub state: SingleLookupRequestState<FixedBlobSidecarList<E>>,
 }
@@ -387,10 +387,10 @@ impl<E: EthSpec> BlobRequestState<E> {
 }
 
 /// The state of the custody request component of a `SingleBlockLookup`.
-#[derive(Derivative)]
-#[derivative(Debug)]
+#[derive(Educe)]
+#[educe(Debug)]
 pub struct CustodyRequestState<E: EthSpec> {
-    #[derivative(Debug = "ignore")]
+    #[educe(Debug(ignore))]
     pub block_root: Hash256,
     pub state: SingleLookupRequestState<DataColumnSidecarList<E>>,
 }
@@ -405,10 +405,10 @@ impl<E: EthSpec> CustodyRequestState<E> {
 }
 
 /// The state of the block request component of a `SingleBlockLookup`.
-#[derive(Derivative)]
-#[derivative(Debug)]
+#[derive(Educe)]
+#[educe(Debug)]
 pub struct BlockRequestState<E: EthSpec> {
-    #[derivative(Debug = "ignore")]
+    #[educe(Debug(ignore))]
     pub requested_block_root: Hash256,
     pub state: SingleLookupRequestState<Arc<SignedBeaconBlock<E>>>,
 }

beacon_node/operation_pool/Cargo.toml

@@ -9,7 +9,7 @@ portable = ["beacon_chain/portable"]
 
 [dependencies]
 bitvec = { workspace = true }
-derivative = { workspace = true }
+educe = { workspace = true }
 ethereum_ssz = { workspace = true }
 ethereum_ssz_derive = { workspace = true }
 itertools = { workspace = true }

beacon_node/operation_pool/src/persistence.rs

@@ -3,7 +3,7 @@ use crate::OperationPool;
 use crate::attestation_storage::AttestationMap;
 use crate::bls_to_execution_changes::{BlsToExecutionChanges, ReceivedPreCapella};
 use crate::sync_aggregate_id::SyncAggregateId;
-use derivative::Derivative;
+use educe::Educe;
 use parking_lot::RwLock;
 use ssz::{Decode, Encode};
 use ssz_derive::{Decode, Encode};
@@ -22,10 +22,7 @@ type PersistedSyncContributions<E> = Vec<(SyncAggregateId, Vec<SyncCommitteeCont
 /// of this type (or its encoded form) for equality. Convert back to an `OperationPool` first.
 #[superstruct(
     variants(V15, V20),
-    variant_attributes(
-        derive(Derivative, PartialEq, Debug, Encode, Decode),
-        derivative(Clone),
-    ),
+    variant_attributes(derive(Educe, PartialEq, Debug, Encode, Decode), educe(Clone),),
     partial_getter_error(ty = "OpPoolError", expr = "OpPoolError::IncorrectOpPoolVariant")
 )]
 #[derive(PartialEq, Debug, Encode)]