From daa811d519cf3fb0bd2bf4d2d54a93b632bdf7b8 Mon Sep 17 00:00:00 2001
From: g11tech <develop@g11tech.io>
Date: Sat, 2 Sep 2023 17:21:17 +0530
Subject: [PATCH] fix: fix breaking builder block production (#5928)

---
 .../src/chain/produceBlock/produceBlockBody.ts            | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/packages/beacon-node/src/chain/produceBlock/produceBlockBody.ts b/packages/beacon-node/src/chain/produceBlock/produceBlockBody.ts
index 2df0f71afa87..1ab87b392150 100644
--- a/packages/beacon-node/src/chain/produceBlock/produceBlockBody.ts
+++ b/packages/beacon-node/src/chain/produceBlock/produceBlockBody.ts
@@ -329,8 +329,14 @@ export async function produceBlockBody<T extends BlockType>(
     (blockBody as capella.BeaconBlockBody).blsToExecutionChanges = blsToExecutionChanges;
     Object.assign(logMeta, {
       blsToExecutionChanges: blsToExecutionChanges.length,
-      withdrawals: (blockBody as capella.BeaconBlockBody).executionPayload.withdrawals.length,
     });
+
+    // withdrawals are only available in full body
+    if (blockType === BlockType.Full) {
+      Object.assign(logMeta, {
+        withdrawals: (blockBody as capella.BeaconBlockBody).executionPayload.withdrawals.length,
+      });
+    }
   }
 
   Object.assign(logMeta, {blockValue});