From 996a0bdcdc76cb6aa7f9ab38d4e633f321dde823 Mon Sep 17 00:00:00 2001
From: Etan Kissling <etan@status.im>
Date: Mon, 5 Dec 2022 20:41:52 +0100
Subject: [PATCH] fix crash when calling MEV rpc with MEV disabled (#4389)

Avoid `/eth/v1/beacon/blinded_blocks` crash without `--payload-builder`.
---
 beacon_chain/validators/message_router_mev.nim | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/beacon_chain/validators/message_router_mev.nim b/beacon_chain/validators/message_router_mev.nim
index 01a5cd94a..34c039e9f 100644
--- a/beacon_chain/validators/message_router_mev.nim
+++ b/beacon_chain/validators/message_router_mev.nim
@@ -48,6 +48,9 @@ proc unblindAndRouteBlockMEV*(
     Future[Result[Opt[BlockRef], string]] {.async.} =
   # By time submitBlindedBlock is called, must already have done slashing
   # protection check
+  if node.payloadBuilderRestClient.isNil:
+    return err "unblindAndRouteBlockMEV: nil REST client"
+
   let unblindedPayload =
     try:
       awaitWithTimeout(