From 853d17df79b8d2994b43820384ec654d82e19f4b Mon Sep 17 00:00:00 2001
From: spypsy <6403450+spypsy@users.noreply.github.com>
Date: Wed, 11 Feb 2026 15:09:22 +0000
Subject: [PATCH] chore: log L1 trace errors once in debug

Fixes [A-393](https://linear.app/aztec-labs/issue/A-393/non-debug-tx-nodes-spam-logs-when-encountering-bad-blocks)
---
 .../src/l1/calldata_retriever.test.ts         | 27 +++++++++++++++++++
 .../archiver/src/l1/calldata_retriever.ts     | 22 +++++++++++++--
 2 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/yarn-project/archiver/src/l1/calldata_retriever.test.ts b/yarn-project/archiver/src/l1/calldata_retriever.test.ts
index 9dd7f5e7187a..0cb5bdf04650 100644
--- a/yarn-project/archiver/src/l1/calldata_retriever.test.ts
+++ b/yarn-project/archiver/src/l1/calldata_retriever.test.ts
@@ -14,6 +14,7 @@ import { GasFees } from '@aztec/stdlib/gas';
 import { ConsensusPayload, SignatureDomainSeparator } from '@aztec/stdlib/p2p';
 import { CheckpointHeader } from '@aztec/stdlib/rollup';
 
+import { jest } from '@jest/globals';
 import { type MockProxy, mock } from 'jest-mock-extended';
 import {
   type Hex,
@@ -1017,6 +1018,32 @@ describe('CalldataRetriever', () => {
       expect(debugClient.request).toHaveBeenCalledTimes(2);
     });
 
+    it('should log trace+debug failure warn only once per tx hash', async () => {
+      CalldataRetriever.resetTraceFailureWarnedForTesting();
+      const warnSpy = jest.spyOn(logger, 'warn');
+
+      // First attempt: both trace and debug fail
+      debugClient.request.mockRejectedValueOnce(new Error('trace_transaction not supported'));
+      debugClient.request.mockRejectedValueOnce(new Error('debug_traceTransaction not supported'));
+
+      await expect(retriever.extractCalldataViaTrace(txHash)).rejects.toThrow(
+        'Failed to trace transaction ' + txHash + ' to extract propose calldata',
+      );
+      expect(warnSpy).toHaveBeenCalledTimes(1);
+      expect(warnSpy).toHaveBeenCalledWith(expect.stringContaining('Cannot decode L1 tx'));
+
+      // Second attempt: same tx, both fail again - should not log warn again
+      debugClient.request.mockRejectedValueOnce(new Error('trace_transaction not supported'));
+      debugClient.request.mockRejectedValueOnce(new Error('debug_traceTransaction not supported'));
+
+      await expect(retriever.extractCalldataViaTrace(txHash)).rejects.toThrow(
+        'Failed to trace transaction ' + txHash + ' to extract propose calldata',
+      );
+      expect(warnSpy).toHaveBeenCalledTimes(1);
+
+      warnSpy.mockRestore();
+    });
+
     it('should throw when no propose calls found', async () => {
       // Mock debug client to return empty trace
       debugClient.request.mockResolvedValueOnce([]);
diff --git a/yarn-project/archiver/src/l1/calldata_retriever.ts b/yarn-project/archiver/src/l1/calldata_retriever.ts
index 84f227b9617b..160123c13338 100644
--- a/yarn-project/archiver/src/l1/calldata_retriever.ts
+++ b/yarn-project/archiver/src/l1/calldata_retriever.ts
@@ -39,6 +39,14 @@ import type { CallInfo } from './types.js';
  * in order to reconstruct an L2 block header.
  */
 export class CalldataRetriever {
+  /** Tx hashes we've already logged for trace+debug failure (log once per tx per process). */
+  private static readonly traceFailureWarnedTxHashes = new Set<string>();
+
+  /** Clears the trace-failure warned set. For testing only. */
+  static resetTraceFailureWarnedForTesting(): void {
+    CalldataRetriever.traceFailureWarnedTxHashes.clear();
+  }
+
   /** Pre-computed valid contract calls for validation */
   private readonly validContractCalls: ValidContractCall[];
 
@@ -313,7 +321,8 @@ export class CalldataRetriever {
       this.logger.debug(`Successfully traced using trace_transaction, found ${calls.length} calls`);
     } catch (err) {
       const traceError = err instanceof Error ? err : new Error(String(err));
-      this.logger.verbose(`Failed trace_transaction for ${txHash}`, { traceError });
+      this.logger.verbose(`Failed trace_transaction for ${txHash}: ${traceError.message}`);
+      this.logger.debug(`Trace failure details for ${txHash}`, { traceError });
 
       try {
         // Fall back to debug_traceTransaction (Geth RPC)
@@ -322,7 +331,16 @@ export class CalldataRetriever {
         this.logger.debug(`Successfully traced using debug_traceTransaction, found ${calls.length} calls`);
       } catch (debugErr) {
         const debugError = debugErr instanceof Error ? debugErr : new Error(String(debugErr));
-        this.logger.warn(`All tracing methods failed for tx ${txHash}`, {
+        // Log once per tx so we don't spam on every sync cycle when sync point doesn't advance
+        if (!CalldataRetriever.traceFailureWarnedTxHashes.has(txHash)) {
+          CalldataRetriever.traceFailureWarnedTxHashes.add(txHash);
+          this.logger.warn(
+            `Cannot decode L1 tx ${txHash}: trace and debug RPC failed or unavailable. ` +
+              `trace_transaction: ${traceError.message}; debug_traceTransaction: ${debugError.message}`,
+          );
+        }
+        // Full error objects can be very long; keep at debug only
+        this.logger.debug(`Trace/debug failure details for tx ${txHash}`, {
           traceError,
           debugError,
           txHash,