fix(test): wait for full gossip mesh before committee produces (A-1219)

yarn-project/end-to-end/src/e2e_p2p/gossip_network_no_cheat.test.ts

@@ -13,7 +13,7 @@ import { sleep } from '@aztec/foundation/sleep';
 import { MockZKPassportVerifierAbi } from '@aztec/l1-artifacts/MockZKPassportVerifierAbi';
 import { RollupAbi } from '@aztec/l1-artifacts/RollupAbi';
 import type { SequencerClient } from '@aztec/sequencer-client';
-import { CheckpointAttestation, ConsensusPayload } from '@aztec/stdlib/p2p';
+import { CheckpointAttestation, ConsensusPayload, TopicType } from '@aztec/stdlib/p2p';
 import { ZkPassportProofParams } from '@aztec/stdlib/zkpassport';
 
 import { jest } from '@jest/globals';
@@ -201,8 +201,21 @@ describe('e2e_p2p_network', () => {
       shouldCollectMetrics(),
     );
 
-    // wait a bit for peers to discover each other
-    await sleep(8000);
+    // Wait for the gossipsub mesh to fully form before the committee starts producing. With
+    // skipInitialSequencer, the first blocks are built by this committee, and the first checkpoint
+    // must reach quorum (all 4 validators) to land on L1. If the proposal/checkpoint meshes are only
+    // partly formed, some committee members miss the first proposal, the first checkpoint stalls at
+    // 2/3, and every later slot rebuilds a competing un-checkpointed block 1 that peers reject as
+    // `block_number_already_exists` — a permanent 2/3 deadlock. Require a full mesh (N-1 peers per
+    // node) on the proposal/checkpoint topics so the first proposal reaches the whole committee.
+    await t.waitForP2PMeshConnectivity(
+      nodes,
+      NUM_VALIDATORS,
+      60,
+      0.5,
+      [TopicType.block_proposal, TopicType.checkpoint_proposal, TopicType.checkpoint_attestation],
+      NUM_VALIDATORS - 1,
+    );
 
     // Wait for the first checkpoint to be published to L1 before submitting transactions.
     // With skipInitialSequencer, no blocks exist from setup, so the first blocks are built by the

yarn-project/end-to-end/src/e2e_p2p/p2p_network.ts

@@ -431,6 +431,7 @@ export class P2PNetworkTest {
     timeoutSeconds = 30,
     checkIntervalSeconds = 0.1,
     topics: TopicType[] = [TopicType.tx],
+    minMeshPeerCount = 1,
   ) {
     const nodeCount = expectedNodeCount ?? nodes.length;
     const minPeerCount = nodeCount - 1;
@@ -457,27 +458,29 @@ export class P2PNetworkTest {
 
     this.logger.warn('All nodes connected to P2P mesh');
 
-    // Wait for GossipSub mesh to form for all specified topics.
-    // We only require at least 1 mesh peer per node because GossipSub
-    // stops grafting once it reaches Dlo peers and won't fill the mesh to all available peers.
+    // Wait for the GossipSub mesh to form for all specified topics. By default we only require at
+    // least 1 mesh peer per node, since GossipSub stops grafting once it reaches Dlo peers and won't
+    // fill the mesh to every available peer. Callers that need a proposal to reach the whole
+    // committee within a slot (e.g. quorum-from-genesis tests) raise `minMeshPeerCount` so the mesh
+    // is fully formed — a single mesh peer can leave some committee members unreached at first.
     for (const topic of topics) {
-      this.logger.warn(`Waiting for GossipSub mesh to form for ${topic} topic...`);
+      this.logger.warn(`Waiting for GossipSub mesh (>= ${minMeshPeerCount} peers per node) for ${topic} topic...`);
       await Promise.all(
         nodes.map(async (node, index) => {
           const p2p = node.getP2P();
           await retryUntil(
             async () => {
               const meshPeers = await p2p.getGossipMeshPeerCount(topic);
               this.logger.debug(`Node ${index} has ${meshPeers} gossip mesh peers for ${topic} topic`);
-              return meshPeers >= 1 ? true : undefined;
+              return meshPeers >= minMeshPeerCount ? true : undefined;
             },
-            `Node ${index} to have gossip mesh peers for ${topic} topic`,
+            `Node ${index} to have >= ${minMeshPeerCount} gossip mesh peers for ${topic} topic`,
             timeoutSeconds,
             checkIntervalSeconds,
           );
         }),
       );
-      this.logger.warn(`All nodes have gossip mesh peers for ${topic} topic`);
+      this.logger.warn(`All nodes have >= ${minMeshPeerCount} gossip mesh peers for ${topic} topic`);
     }
   }