Lesson 7: VirtualMachineError when calling endLottery function

[rsamban]

I am getting following error when calling endLottery function. Not sure what I am missing. Can you please help?

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Brownie v1.17.2 - Python development framework for Ethereum

SmartcontractLotteryProject is the active project.

Launching 'ganache-cli --accounts 10 --hardfork istanbul --gasLimit 12000000 --mnemonic brownie --port 8545'...

Running 'scripts/deploy_lottery.py::main'...
Transaction sent: 0x13207324e29c4b959f1354eac94b6ed842b051dae3aad9f3db0c0c13ef4012a3
Gas price: 0.0 gwei Gas limit: 12000000 Nonce: 0
MockV3Aggregator.constructor confirmed Block: 1 Gas used: 430659 (3.59%)
MockV3Aggregator deployed at: 0x3194cBDC3dbcd3E11a07892e7bA5c3394048Cc87

Transaction sent: 0xe32677f021ed8131944b28cbc57e3fe75a1b28b3f10041e89cebcfd90a8d338f
Gas price: 0.0 gwei Gas limit: 12000000 Nonce: 1
LinkToken.constructor confirmed Block: 2 Gas used: 669136 (5.58%)
LinkToken deployed at: 0x602C71e4DAC47a042Ee7f46E0aee17F94A3bA0B6

Transaction sent: 0xc509c872ecebb1dddb54a37b841a38553731c2d925ee7c0034357eed4e32cb08
Gas price: 0.0 gwei Gas limit: 12000000 Nonce: 2
VRFCoordinatorMock.constructor confirmed Block: 3 Gas used: 276395 (2.30%)
VRFCoordinatorMock deployed at: 0xE7eD6747FaC5360f88a2EFC03E00d25789F69291

Transaction sent: 0x344666c4ca24d48671f492c0f26abfac18fc0228e7d5e8a2002f3ec7289edcf8
Gas price: 0.0 gwei Gas limit: 12000000 Nonce: 3
Lottery.constructor confirmed Block: 4 Gas used: 896904 (7.47%)
Lottery deployed at: 0x6951b5Bd815043E3F842c1b026b0Fa888Cc2DD85

network:::{'gas_limit': 'max', 'gas_buffer': 1, 'gas_price': 0, 'max_fee': None, 'priority_fee': None, 'reverting_tx_gas_limit': 'max', 'default_contract_owner': True, 'cmd_settings': None, 'keyhash': '0x2ed0feb3e7fd2022120aa84fab1945545a9f2ffc9076fd6156fa96eaff4c1311', 'fee': 100000000000000000}
Deployed Lottery
Transaction sent: 0x1f3629b4ccc88f7e9e8b4f9d7d7a0e3328610fafa9346bd79152467364540969
Gas price: 0.0 gwei Gas limit: 12000000 Nonce: 4
Lottery.startLottery confirmed Block: 5 Gas used: 28902 (0.24%)

Lottery.startLottery confirmed Block: 5 Gas used: 28902 (0.24%)

Lottery Started!
Transaction sent: 0xda214dddeb9bc33dab1c188730bf5ec64d0a996de7e367299176ac595944dfbf
Gas price: 0.0 gwei Gas limit: 12000000 Nonce: 5
Lottery.enter confirmed Block: 6 Gas used: 70995 (0.59%)

Lottery.enter confirmed Block: 6 Gas used: 70995 (0.59%)

Entered Lottery!
Transaction sent: 0xf7b3761cd940dde0b042ff692416df3b66be04dd22ececfdcd8f2230317a6cc7
Gas price: 0.0 gwei Gas limit: 12000000 Nonce: 6
LinkToken.transfer confirmed Block: 7 Gas used: 51386 (0.43%)

LinkToken.transfer confirmed Block: 7 Gas used: 51386 (0.43%)

Contract Finded!
LinkToken.transfer confirmed Block: 7 Gas used: 51386 (0.43%)

Transaction sent: 0xe97361a7db515a30e3feac79b1e14d6e16abd3132949b17a82fbb83cd87bc619
Gas price: 0.0 gwei Gas limit: 12000000 Nonce: 7
Lottery.endLottery confirmed (reverted) Block: 8 Gas used: 11813033 (98.44%)

File "brownie/_cli/run.py", line 50, in main
return_value, frame = run(
File "brownie/project/scripts.py", line 103, in run
return_value = f_locals[method_name](*args, **kwargs)
File "./scripts/deploy_lottery.py", line 59, in main
end_lottery()
File "./scripts/deploy_lottery.py", line 48, in end_lottery
tx = lottery.endLottery({"from": account})
File "brownie/network/contract.py", line 1629, in call
return self.transact(*args)
File "brownie/network/contract.py", line 1502, in transact
return tx["from"].transfer(
File "brownie/network/account.py", line 682, in transfer
receipt._raise_if_reverted(exc)
File "brownie/network/transaction.py", line 446, in _raise_if_reverted
raise exc._with_attr(
VirtualMachineError: revert
Trace step -1, program counter 2468:
File "/Users/rsamban/.brownie/packages/smartcontractkit/[email protected]/contracts/src/v0.6/VRFConsumerBase.sol", line 161, in VRFConsumerBase.requestRandomness:
function requestRandomness(bytes32 _keyHash, uint256 _fee)
internal returns (bytes32 requestId)
{
LINK.transferAndCall(vrfCoordinator, _fee, abi.encode(_keyHash, USER_SEED_PLACEHOLDER));
// This is the seed passed to VRFCoordinator. The oracle will mix this with
// the hash of the block containing this request to obtain the seed/input
// which is finally passed to the VRF cryptographic machinery.
Terminating local RPC client...

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[cromewar]

Hello @rsamban as the error says the problem is with your request randomness function, could you please share here your contract code in order to check it?

[rsamban]

@cromewar Thanks for your response. Following is how I can reproduce this.
$ git clone https://github.com/PatrickAlphaC/smartcontract-lottery.git smartcontract-lottery-orig
$ cd smartcontract-lottery-orig
$ brownie compile
$ brownie run scripts/deploy_lottery.py

// Above Works fine.

However, when I replace fund_with_link function in helpful_scripts.py with following I get the above error.

def fund_with_link(
    contract_address, account=None, link_token=None, amount=20000000000000000
):  # 0.1 LINK
    account = account if account else get_account()
    link_token = link_token if link_token else get_contract("link_token")
    tx = link_token.transfer(contract_address, amount, {"from": account})
    # link_token_contract = interface.LinkTokenInterface(link_token.address)
    # tx = link_token_contract.transfer(contract_address, amount, {"from": account})
    tx.wait(1)
    print("Contract Funded!")
    return tx

So I believe the problem is with this function, but I can't figure it out.
I can get my code working when I replace the one from the repo.
I can keep going now, but it is just annoying..., it is just one small comma or period, which is taking > couple of hours. Agh...

As requested, i have attached my Logger.sol also - just in case
Lottery.TXT
.

[cromewar]

Well the problem is with the amount as far as it seems, you are using 20000000000000000 which has 17 digits and you should use something with 18 digits, try this instead:

def fund_with_link(
    contract_address, account=None, link_token=None, amount=100000000000000000
):  # 0.1 link
    account = account if account else get_account()
    link_token = link_token if link_token else get_contract("link_token")
    tx = link_token.transfer(contract_address, amount, {"from": account})
    # link_token_contract = interface.LinkTokenInterface(link_token.address)
    # tx = link_token_contract.transfer(contract_address, amount, {"from": account})
    tx.wait(1)
    print("Fund contract successful")
    return tx

[rsamban]

Yes, it was, thanks @cromewar

[cromewar]

I'm glad is solved now.