feat(rpc): implement debug_traceBadBlock (#22719)

crates/rpc/rpc-api/src/debug.rs

@@ -404,7 +404,7 @@ pub trait DebugApi<TxReq: RpcObject> {
         &self,
         block_hash: B256,
         opts: Option<GethDebugTracingCallOptions>,
-    ) -> RpcResult<()>;
+    ) -> RpcResult<Vec<TraceResult>>;
 
     /// Sets the logging verbosity ceiling. Log messages with level up to and including the given
     /// level will be printed.

crates/rpc/rpc/src/debug.rs

@@ -1070,10 +1070,25 @@ where
 
     async fn debug_trace_bad_block(
         &self,
-        _block_hash: B256,
-        _opts: Option<GethDebugTracingCallOptions>,
-    ) -> RpcResult<()> {
-        Ok(())
+        block_hash: B256,
+        opts: Option<GethDebugTracingCallOptions>,
+    ) -> RpcResult<Vec<TraceResult>> {
+        let _permit = self.acquire_trace_permit().await;
+        let block = self
+            .inner
+            .bad_block_store
+            .get(block_hash)
+            .ok_or_else(|| internal_rpc_err("bad block not found in cache"))?;
+
+        let evm_env = self
+            .eth_api()
+            .evm_config()
+            .evm_env(block.header())
+            .map_err(RethError::other)
+            .to_rpc_result()?;
+
+        let opts = opts.map(|o| o.tracing_options).unwrap_or_default();
+        self.trace_block(block, evm_env, opts).await.map_err(Into::into)
     }
 
     async fn debug_verbosity(&self, _level: usize) -> RpcResult<()> {
@@ -1153,6 +1168,12 @@ impl<B: BlockTrait> BadBlockStore<B> {
         let guard = self.inner.read();
         guard.iter().rev().cloned().collect()
     }
+
+    /// Returns the bad block with the given hash, if cached.
+    fn get(&self, hash: B256) -> Option<Arc<RecoveredBlock<B>>> {
+        let guard = self.inner.read();
+        guard.iter().find(|b| b.hash() == hash).cloned()
+    }
 }
 
 impl<B: BlockTrait> Default for BadBlockStore<B> {