Use derivative to avoid manual Clone impl

Cargo.toml

@@ -185,6 +185,7 @@ ctrlc = "3.4.2"
 curve25519-dalek = "3.2.1"
 dashmap = "5.5.3"
 derivation-path = { version = "0.2.0", default-features = false }
+derivative = "2.2.0"
 dialoguer = "0.10.4"
 digest = "0.10.7"
 dir-diff = "0.3.3"

unified-scheduler-pool/Cargo.toml

@@ -12,6 +12,7 @@ edition = { workspace = true }
 [dependencies]
 assert_matches = { workspace = true }
 crossbeam-channel = { workspace = true }
+derivative = { workspace = true }
 log = { workspace = true }
 solana-ledger = { workspace = true }
 solana-program-runtime = { workspace = true }

unified-scheduler-pool/src/lib.rs

@@ -11,6 +11,7 @@
 use {
     assert_matches::assert_matches,
     crossbeam_channel::{select, unbounded, Receiver, SendError, Sender},
+    derivative::Derivative,
     log::*,
     solana_ledger::blockstore_processor::{
         execute_batch, TransactionBatchWithIndexes, TransactionStatusSender,
@@ -326,20 +327,15 @@ mod chained_channel {
         }
     }
 
+    // P doesn't need to be `: Clone`, yet rustc derive can't handle it.
+    // see https://github.com/rust-lang/rust/issues/26925
+    #[derive(Derivative)]
+    #[derivative(Clone(bound = "C: Clone"))]
     pub(super) struct ChainedChannelReceiver<P, C: Clone> {
         receiver: Receiver<ChainedChannel<P, C>>,
         context: C,
     }
 
-    impl<P, C: Clone> Clone for ChainedChannelReceiver<P, C> {
-        fn clone(&self) -> Self {
-            Self {
-                receiver: self.receiver.clone(),
-                context: self.context.clone(),
-            }
-        }
-    }
-
     impl<P, C: Clone> ChainedChannelReceiver<P, C> {
         fn new(receiver: Receiver<ChainedChannel<P, C>>, initial_context: C) -> Self {
             Self {