From 0b93eeeaaf462f23634b696345ece659b17f5695 Mon Sep 17 00:00:00 2001
From: tersec <tersec@users.noreply.github.com>
Date: Thu, 15 Sep 2022 15:00:23 +0200
Subject: [PATCH] delay first exchangeTransitionConfiguration (#4114)

---
 beacon_chain/eth1/eth1_monitor.nim  | 13 ++++++++++++-
 beacon_chain/nimbus_beacon_node.nim |  8 +++++++-
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/beacon_chain/eth1/eth1_monitor.nim b/beacon_chain/eth1/eth1_monitor.nim
index 2d9d3ecd6..c18415775 100644
--- a/beacon_chain/eth1/eth1_monitor.nim
+++ b/beacon_chain/eth1/eth1_monitor.nim
@@ -1539,7 +1539,9 @@ proc startEth1Syncing(m: Eth1Monitor, delayBeforeStart: Duration) {.async.} =
         BELLATRIX_FORK_EPOCH = m.cfg.BELLATRIX_FORK_EPOCH,
         totalDifficulty = $nextBlock.totalDifficulty,
         ttd = $m.cfg.TERMINAL_TOTAL_DIFFICULTY,
-        terminalBlockHash = m.terminalBlockHash
+        terminalBlockHash = m.terminalBlockHash,
+        candidateBlockHash = terminalBlockCandidate.hash,
+        candidateBlockNumber = distinctBase(terminalBlockCandidate.number)
 
       if terminalBlockCandidate.totalDifficulty >= m.cfg.TERMINAL_TOTAL_DIFFICULTY:
         while not terminalBlockCandidate.parentHash.isZeroMemory:
@@ -1551,6 +1553,15 @@ proc startEth1Syncing(m: Eth1Monitor, delayBeforeStart: Duration) {.async.} =
         m.terminalBlockHash = some terminalBlockCandidate.hash
         m.terminalBlockNumber = some terminalBlockCandidate.number
 
+        debug "startEth1Syncing: found merge terminal block",
+          currentEpoch = m.currentEpoch,
+          BELLATRIX_FORK_EPOCH = m.cfg.BELLATRIX_FORK_EPOCH,
+          totalDifficulty = $nextBlock.totalDifficulty,
+          ttd = $m.cfg.TERMINAL_TOTAL_DIFFICULTY,
+          terminalBlockHash = m.terminalBlockHash,
+          candidateBlockHash = terminalBlockCandidate.hash,
+          candidateBlockNumber = distinctBase(terminalBlockCandidate.number)
+
     if shouldProcessDeposits:
       if m.latestEth1BlockNumber <= m.cfg.ETH1_FOLLOW_DISTANCE:
         continue
diff --git a/beacon_chain/nimbus_beacon_node.nim b/beacon_chain/nimbus_beacon_node.nim
index b6686e0d8..4b95be041 100644
--- a/beacon_chain/nimbus_beacon_node.nim
+++ b/beacon_chain/nimbus_beacon_node.nim
@@ -742,7 +742,13 @@ proc init*(T: type BeaconNode,
     beaconClock: beaconClock,
     validatorMonitor: validatorMonitor,
     stateTtlCache: stateTtlCache,
-    nextExchangeTransitionConfTime: Moment.now,
+    nextExchangeTransitionConfTime:
+      # https://github.com/ethereum/execution-apis/blob/v1.0.0-beta.1/src/engine/specification.md#specification-3
+      # Consensus Layer client software **SHOULD** poll this endpoint every
+      # 60 seconds.
+      # Delay first call by that time to allow for EL syncing to begin; it can
+      # otherwise generate an EL warning by claiming a zero merge block.
+      Moment.now + chronos.seconds(60),
     dynamicFeeRecipientsStore: newClone(DynamicFeeRecipientsStore.init()))
 
   node.initLightClient(