[BUG] Gas refund amount is different from reported block explorer

[dutterbutter]

🐛 Bug Report for anvil-zksync

📝 Description

Replaying the following tx:

anvil-zksync -d replay_tx --fork-url sepolia-testnet 0x46c0db5b243cec2ef4016143a7f17718815420f0e863197b432f4231a1b2c57c 

We see the following details:

17:08:40  INFO ✅  [SUCCESS] Hash: 0x46c0db5b243cec2ef4016143a7f17718815420f0e863197b432f4231a1b2c57c
17:08:40  INFO Initiator: 0xe85b66fca403bc35bcae17ce7758e942aea65dc0
17:08:40  INFO Payer: 0xe85b66fca403bc35bcae17ce7758e942aea65dc0
17:08:40  INFO Gas Limit: 264_868 | Used: 129_640 | Refunded: 135_228
17:08:40  INFO Paid: 0.0000032410 ETH (129640 gas * 0.02500000 gwei)
17:08:40  INFO Refunded: 0.0000033807 ETH

The refund specified is Refunded: 0.0000033807 ETH whereas if we review the tx on the block explorer it is reported as Refunded: 0.0000044942 ETH

As a result the calculation for fees is also different.

🔄 Reproduction Steps

1. Step 1
2. Step 2
3. ...

🤔 Expected Behavior

Replayed refund amount should be the same as reported on block explorer.

😯 Current Behavior

Discrepancy on refund amount.

🖥️ Environment

• Rust version: [e.g., rustc 1.52.0]
• Operating System & Version: [e.g., Ubuntu 20.04]
• Other relevant environment details:

📋 Additional Context

Add any other context about the problem here. If applicable, add screenshots to help explain.

📎 Log Output

Paste any relevant log output here.

[dutterbutter]

So the refund amount reported by the block explorer 179_768 units of gas which equals 0.0000044942 ETH. We are reporting 135_228 units of gas which equals 0.0000033807 ETH.

We are receiving the refund value from the tx_result VmExecutionResultAndLogs so I am not sure where the discrepancy is coming from.