Fixing block hang on syncing empty blocks

packages/contracts/src/deployment/contract-deploy.ts

@@ -32,7 +32,7 @@ const deployContract = async (
 
   const deployResult = await config.signer.sendTransaction({
     data: rawTx.data,
-    gasLimit: 9_500_000,
+    gasLimit: 7_500_000,
     gasPrice: 2_000_000_000,
     value: 0,
     nonce: await config.signer.getTransactionCount('pending'),

packages/core-db/src/app/ethereum/ethereum-block-processor.ts

@@ -1,5 +1,5 @@
 /* External Imports */
-import { getLogger, logError } from '@eth-optimism/core-utils'
+import { getLogger, logError, sleep } from '@eth-optimism/core-utils'
 import { Block, Provider, TransactionReceipt } from 'ethers/providers'
 
 /* Internal Imports */
@@ -112,11 +112,28 @@ export class EthereumBlockProcessor {
         `Waiting for ${this.confirmsUntilFinal} confirms before disseminating block ${blockNumber}`
       )
       try {
-        const receipt: TransactionReceipt = await provider.waitForTransaction(
-          (block.transactions[0] as any).hash,
-          this.confirmsUntilFinal
-        )
-        if (receipt.blockHash !== block.hash) {
+        let refetchedHash: string
+        if (block.transactions.length > 0) {
+          const receipt: TransactionReceipt = await provider.waitForTransaction(
+            (block.transactions[0] as any).hash,
+            this.confirmsUntilFinal
+          )
+          refetchedHash = receipt.blockHash
+        } else {
+          while (
+            (await provider.getBlockNumber()) <
+            blockNumber + this.confirmsUntilFinal
+          ) {
+            log.debug(
+              `Waiting for empty block ${blockNumber} to be final. Sleeping...`
+            )
+            await sleep(15_000)
+          }
+          const refetched = await provider.getBlock(blockNumber)
+          refetchedHash = refetched.hash
+        }
+
+        if (refetchedHash !== block.hash) {
           log.info(
             `Re-org processing block number ${blockNumber}. Re-fetching block.`
           )