Merge branch 'backport-to-v4-next-staging' into claudebox/backport-22493-v4-next

Author: benesjan

yarn-project/pxe/src/block_synchronizer/block_synchronizer.ts

@@ -77,6 +77,8 @@ export class BlockSynchronizer implements L2BlockStreamEventHandler {
           const blockHeader = await this.node.getBlockHeader(BlockNumber(event.block.number));
           if (blockHeader) {
             await this.updateAnchorBlockHeader(blockHeader);
+          } else {
+            this.log.warn(`Block header not found for proven block ${event.block.number}, skipping anchor update`);
           }
         }
         break;
@@ -86,6 +88,8 @@ export class BlockSynchronizer implements L2BlockStreamEventHandler {
           const blockHeader = await this.node.getBlockHeader(BlockNumber(event.block.number));
           if (blockHeader) {
             await this.updateAnchorBlockHeader(blockHeader);
+          } else {
+            this.log.warn(`Block header not found for finalized block ${event.block.number}, skipping anchor update`);
           }
         }
         break;
@@ -152,6 +156,8 @@ export class BlockSynchronizer implements L2BlockStreamEventHandler {
     }
 
     this.log.debug(`Syncing PXE with the node`);
+    // Capture the promise locally so we always await the exact promise we created, even if this.isSyncing is modified
+    // between assignment and await (e.g. due to future refactors introducing a yield point).
     const isSyncing = this.doSync();
     this.isSyncing = isSyncing;
     try {