From acfdd2b22e9fb756e559bad7c4a719eaf1238dc9 Mon Sep 17 00:00:00 2001
From: openhands <openhands@all-hands.dev>
Date: Thu, 12 Mar 2026 07:57:31 +0000
Subject: [PATCH] fix: fix: Debug failing round-trip-safe attack in evolution
 fitness (#595)
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After a buy→sell round-trip the net price movement is near zero, so
recenter() reverts with "amplitude not reached" and aborts the whole
AttackRunner script.

Wrap the recenter() call in a try/catch so amplitude failures are
caught and logged as a skipped step rather than propagating as a fatal
revert.  When recenter is skipped, no state snapshot is emitted and the
attack sequence continues — matching the intended semantics: round-trip
trading should not cause the fitness scorer to crash.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 onchain/script/backtesting/AttackRunner.s.sol | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/onchain/script/backtesting/AttackRunner.s.sol b/onchain/script/backtesting/AttackRunner.s.sol
index 351ee35..10d2bd7 100644
--- a/onchain/script/backtesting/AttackRunner.s.sol
+++ b/onchain/script/backtesting/AttackRunner.s.sol
@@ -252,13 +252,18 @@ contract AttackRunner is Script {
             _executeSell(line);
         } else if (_eq(op, "recenter")) {
             vm.startBroadcast(RECENTER_PK);
-            // Capture direction: true = price moved up, false = price moved down.
-            // recenter() reverts (not returns false) when amplitude is insufficient,
-            // so a successful call is always a real recenter regardless of direction.
-            _lastRecenterIsUp = ILM(lmAddr).recenter();
-            _hasRecentered = true;
+            // recenter() reverts when amplitude is insufficient (price hasn't moved far enough
+            // from the anchor center).  Use try/catch so attacks with round-trip buy→sell cycles
+            // — where the net price movement is near zero — don't abort the whole script.
+            // A caught revert means no state change occurred; skip the snapshot for this step.
+            try ILM(lmAddr).recenter() returns (bool isUp) {
+                _lastRecenterIsUp = isUp;
+                _hasRecentered = true;
+                isRecenter = true;
+            } catch {
+                console.log("recenter: skipped (amplitude not reached)");
+            }
             vm.stopBroadcast();
-            isRecenter = true;
         } else if (_eq(op, "stake")) {
             _executeStake(line);
         } else if (_eq(op, "unstake")) {