fix suggestions

crates/optimism/rpc/src/eth/transaction.rs

@@ -29,6 +29,8 @@ pub enum TransactionError {
     ProviderError(ProviderError),
 }
 
+impl core::error::Error for TransactionError {}
+
 impl<N> EthTransactions for OpEthApi<N>
 where
     Self: LoadTransaction<Provider: BlockReaderIdExt>,

crates/rpc/rpc-types-compat/src/transaction/mod.rs

@@ -3,6 +3,7 @@ mod signature;
 
 pub use signature::*;
 
+use core::error;
 use std::fmt;
 
 use alloy_consensus::Transaction as _;
@@ -48,7 +49,7 @@ pub trait TransactionCompat: Send + Sync + Unpin + Clone + fmt::Debug {
         + fmt::Debug;
 
     /// RPC transaction error type.
-    type TransactionError: fmt::Debug;
+    type TransactionError: error::Error;
 
     ///
     /// Formats gas price and max fee per gas for RPC transaction response w.r.t. network specific

crates/rpc/rpc/src/eth/helpers/types.rs

@@ -1,5 +1,7 @@
 //! L1 `eth` API types.
 
+use std::convert::Infallible;
+
 use alloy_consensus::Transaction as _;
 use alloy_network::{Ethereum, Network};
 use alloy_primitives::{Address, TxKind};
@@ -20,7 +22,7 @@ where
 {
     type Transaction = <Ethereum as Network>::TransactionResponse;
 
-    type TransactionError = ();
+    type TransactionError = Infallible;
 
     fn fill(
         &self,