too many values to unpack (expected 2) on some ContractEvents subscriptions

[mortimr]

Environment information

• ape and plugin versions:

$ ape --version
0.8.22

$ ape plugins list
No plugins installed

$ silverback --version
0.6.5

• Python Version: 3.12.3
• OS: osx

What went wrong?

I tested silverback by setting up a simple bot to poll on a Stake event on a contract. Some events (it seems the ones that have tuples and custom types in their ABIs) are crashing silverback at startup. Only having the handler with the decorator on the problematic event causes the crash, so it does happen right when silverback starts and not when an event is actually received.

Here's the bot I have

from silverback import SilverbackBot
from ape import Contract

bot = SilverbackBot()

abi = """
[
  {
    "type": "event",
    "name": "Stake",
    "inputs": [
      {
        "name": "staker",
        "type": "address",
        "indexed": true,
        "internalType": "address"
      },
      {
        "name": "recipient",
        "type": "address",
        "indexed": true,
        "internalType": "address"
      },
      {
        "name": "depositedEth",
        "type": "uint128",
        "indexed": false,
        "internalType": "uint128"
      },
      {
        "name": "mintedTokens",
        "type": "uint128",
        "indexed": false,
        "internalType": "uint128"
      },
      {
        "name": "stakeDetails",
        "type": "tuple[]",
        "indexed": false,
        "internalType": "struct PoolStakeDetails[]",
        "components": [
          {
            "name": "poolId",
            "type": "uint128",
            "internalType": "uint128"
          },
          {
            "name": "ethToPool",
            "type": "uint128",
            "internalType": "uint128"
          },
          {
            "name": "ethToIntegrator",
            "type": "uint128",
            "internalType": "uint128"
          },
          {
            "name": "pSharesFromPool",
            "type": "uint128",
            "internalType": "uint128"
          },
          {
            "name": "pSharesFromIntegrator",
            "type": "uint128",
            "internalType": "uint128"
          }
        ]
      }
    ],
    "anonymous": false
  }
]
"""

contract_instance = Contract(address="0x2401c39d7ba9e283668a53fcc7b8f5fd9e716fdf", abi=abi)

@bot.on_(contract_instance.Stake)
def handle_stake():
    print("transfer")

And here's the output I get

➜  silverback silverback run ocv2 --network ethereum:mainnet:$ETH_RPC_URL

INFO:     Connecting to existing Geth node at xxx.
INFO:     Loading Silverback Bot with settings:
  BOT_NAME="bot"
  BROKER_CLASS="taskiq:InMemoryBroker"
  NETWORK_CHOICE="ethereum:mainnet:node"
SUCCESS:  Loaded Silverback Bot:
  NETWORK="ethereum:mainnet"
  FORK_MODE=False
  SIGNER=None
INFO:     Connecting to existing Geth node at xxx.
INFO:     Using PollingRunner: max_exceptions=10
WARNING:  The polling runner makes a significant amount of requests. Do not use in production over long time periods unless you know what you're doing.
INFO:     Worker using Silverback SDK v0.6.5, available task types:
- system:config
- user:event-log
- system:user-all-taskdata
- user:startup
- system:load-snapshot
- user:shutdown
- system:user-taskdata
- system:create-snapshot
- user:new-block
WARNING:  Runtime error(s) detected, shutting down:
too many values to unpack (expected 2)

And exits right after.

I also tried to see if the issue came from ape and made a small script to do the polling manually, but everything works wite ape.

from ape import Contract
from ape.cli import ConnectedProviderCommand
import click

abi = """
[
  {
    "type": "event",
    "name": "Stake",
    "inputs": [
      {
        "name": "staker",
        "type": "address",
        "indexed": true,
        "internalType": "address"
      },
      {
        "name": "recipient",
        "type": "address",
        "indexed": true,
        "internalType": "address"
      },
      {
        "name": "depositedEth",
        "type": "uint128",
        "indexed": false,
        "internalType": "uint128"
      },
      {
        "name": "mintedTokens",
        "type": "uint128",
        "indexed": false,
        "internalType": "uint128"
      },
      {
        "name": "stakeDetails",
        "type": "tuple[]",
        "indexed": false,
        "internalType": "struct PoolStakeDetails[]",
        "components": [
          {
            "name": "poolId",
            "type": "uint128",
            "internalType": "uint128"
          },
          {
            "name": "ethToPool",
            "type": "uint128",
            "internalType": "uint128"
          },
          {
            "name": "ethToIntegrator",
            "type": "uint128",
            "internalType": "uint128"
          },
          {
            "name": "pSharesFromPool",
            "type": "uint128",
            "internalType": "uint128"
          },
          {
            "name": "pSharesFromIntegrator",
            "type": "uint128",
            "internalType": "uint128"
          }
        ]
      }
    ],
    "anonymous": false
  }
]
"""


@click.command(cls=ConnectedProviderCommand)
def cli(network, provider):
    contract_address = "0x2401c39d7ba9e283668a53fcc7b8f5fd9e716fdf"
    contract_instance = Contract(address=contract_address, abi=abi)
    for event in contract_instance.Stake.poll_logs():
        print(event)

And it works as expected, I see logs when the events are found onchain.

Any idea on where the issue might be coming from ? I'm also unable to see any additional traces, and even with max verbosity I have no additional clues.
I can help and give more info / run local tests if needed !

Some of the things I tried, without success:

• adding more/less parameters to the handler
• manually tweak the abi to replace the custom type with native types

[linear]

SBK-619 `too many values to unpack (expected 2)` on some ContractEvents subscriptions

[fubuloubu]

handle_stake requires 1 argument for the log data structure from each event log. so change it like this and it should work:

...


@bot.on_(contract_instance.Stake)
def handle_stake(log):
    print("transfer")

[fubuloubu]

However, will leave this open since the error message should be easier to understand

[mortimr]

Sorry, copied the bot script in the latest state I left it. As I mentioned at the end of the issue, I did actually try several combinations for the handler params but still get the error.

I just double checked now with

@bot.on_(contract_instance.Stake)
def handle_stake(stake):
    print("stake", stake)

and got the exact same error

I also tested other events from the same contract

• simple ones like Transfer work properly
• there's another event with a custom type that gives me the exact same trouble

Here the other event ABI

  {
    "type": "event",
    "name": "Exit",
    "inputs": [
      {
        "name": "staker",
        "type": "address",
        "indexed": true,
        "internalType": "address"
      },
      {
        "name": "exitedTokens",
        "type": "uint128",
        "indexed": false,
        "internalType": "uint128"
      },
      {
        "name": "exitDetails",
        "type": "tuple[]",
        "indexed": false,
        "internalType": "struct PoolExitDetails[]",
        "components": [
          {
            "name": "poolId",
            "type": "uint128",
            "internalType": "uint128"
          },
          {
            "name": "exitedPoolShares",
            "type": "uint128",
            "internalType": "uint128"
          }
        ]
      }
    ],
    "anonymous": false
  }

It does feel like there's an issue with tuple[] support

[mortimr]

Just tested again and it seems that the issue is still here with ape 0.8.24 :/

[dtdang]

Just tested again and it seems that the issue is still here with ape 0.8.24 :/

Taking a look at this bug now. I can replicate this error with what you've provided so working on a fix for this.