Attribute Error 'NoneType' object has no attribute 'poll'

[JMiddey]

I am getting the following error when trying to test my lottery (from video part @06:28:00) brownie test --network mainnet-fork Brownie v1.16.4 - Python development framework for Ethereum

======================================================================================== test session starts ======================================================================================== platform darwin -- Python 3.10.1, pytest-6.2.5, py-1.10.0, pluggy-1.0.0 rootdir: /Users/joe/demos/smartcontract-lottery plugins: eth-brownie-1.16.4, hypothesis-6.21.6, xdist-1.34.0, web3-5.23.1, forked-1.3.0 collected 1 item

Launching 'ganache-cli --accounts 10 --fork https://eth-mainnet.alchemyapi.io/v2/NrlINoZBBBd2iLXJVLulIPdGk6UEczAF --mnemonic brownie --port 7545 --hardfork istanbul'... Terminating local RPC client... INTERNALERROR> Traceback (most recent call last): INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/_pytest/main.py", line 269, in wrap_session INTERNALERROR> session.exitstatus = doit(config, session) or 0 INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/_pytest/main.py", line 322, in _main INTERNALERROR> config.hook.pytest_collection(session=session) INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pluggy/_hooks.py", line 265, in call INTERNALERROR> return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult) INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pluggy/_manager.py", line 80, in _hookexec INTERNALERROR> return self._inner_hookexec(hook_name, methods, kwargs, firstresult) INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pluggy/_callers.py", line 60, in _multicall INTERNALERROR> return outcome.get_result() INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pluggy/_result.py", line 60, in get_result INTERNALERROR> raise ex[1].with_traceback(ex[2]) INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pluggy/_callers.py", line 39, in _multicall INTERNALERROR> res = hook_impl.function(*args) INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/_pytest/main.py", line 333, in pytest_collection INTERNALERROR> session.perform_collect() INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/_pytest/main.py", line 641, in perform_collect INTERNALERROR> hook.pytest_collection_finish(session=self) INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pluggy/_hooks.py", line 265, in call INTERNALERROR> return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult) INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pluggy/_manager.py", line 80, in _hookexec INTERNALERROR> return self._inner_hookexec(hook_name, methods, kwargs, firstresult) INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/pluggy/_callers.py", line 55, in _multicall INTERNALERROR> gen.send(outcome) INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/brownie/test/managers/runner.py", line 258, in pytest_collection_finish INTERNALERROR> brownie.network.connect(CONFIG.argv["network"]) INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/brownie/network/main.py", line 50, in connect INTERNALERROR> rpc.launch(active["cmd"], **active["cmd_settings"]) INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/brownie/network/rpc/init.py", line 95, in launch INTERNALERROR> raise RPCConnectionError(cmd, self.process, uri) INTERNALERROR> File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/brownie/exceptions.py", line 41, in init INTERNALERROR> f"\n\nCommand: {cmd}\nURI: {uri}\nExit Code: {proc.poll()}" INTERNALERROR> AttributeError: 'NoneType' object has no attribute 'poll'

====================================================================================== no tests ran in 12.06s =======================================================================================

Lottery.sol file = //SPDX-License-Identifier: MIT pragma solidity ^0.6.6;

import "@chainlink/contracts/src/v0.6/interfaces/AggregatorV3Interface.sol";

contract Lottery { address payable[] public players; uint256 public usdEntryFee; AggregatorV3Interface internal ethUsdPriceFeed;

constructor(address _priceFeedAddress) public {
    usdEntryFee = 50 * (10**18);
    ethUsdPriceFeed = AggregatorV3Interface(_priceFeedAddress);
}

function enter() public payable {
    //minimum USD
    players.push(msg.sender);
}

function getEntranceFee() public view returns (uint256) {
    (, int256 price, , , ) = ethUsdPriceFeed.latestRoundData();
    uint256 adjustedPrice = uint256(price) * 10**10;
    uint256 costToEnter = (usdEntryFee * 10**18) / adjustedPrice;
    return costToEnter;
}

function startLottery() public {}

function endLottery() public {}

}

Test_lottery.py = from brownie import Lottery, accounts, network, config from web3 import Web3

def test_get_entrance_fee(): account = accounts[0] lottery = Lottery.deploy( config["networks"][network.show_active()]["eth_usd_price_feed"], {"from": account}, ) assert lottery.getEntranceFee() > Web3.toWei(0.018, "ether") assert lottery.getEntranceFee() < Web3.toWei(0.022, "ether")

config = dependencies:

• smartcontractkit/chainlink-brownie-contracts@1.1.1 compiler: solc: remappings:
  • '@chainlink=smartcontractkit/chainlink-brownie-contracts@1.1.1'

networks: mainnet-fork: eth_usd_price_feed: '0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419'

[cromewar]

I would pretty much suggest you to use python version 3.8, the latest ones have been reported as not fully compatible with web3 libraries.

[JMiddey]

I have switched my python version to 3.8, but in the code it still says Python 3.10.1, why is that? I have closed and opened a new terminal so don't think thats the reason joe@Joes-MacBook-Pro smartcontract-lottery % python3 --version Python 3.8.0 joe@Joes-MacBook-Pro smartcontract-lottery % python --version Python 2.7.18 joe@Joes-MacBook-Pro smartcontract-lottery % brownie test Brownie v1.16.4 - Python development framework for Ethereum

======================================================================================== test session starts ======================================================================================== platform darwin -- Python 3.10.1, pytest-6.2.5, py-1.10.0, pluggy-1.0.0 rootdir: /Users/joe/demos/smartcontract-lottery plugins: eth-brownie-1.16.4, hypothesis-6.21.6, xdist-1.34.0, web3-5.23.1, forked-1.3.0 collected 1 item

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

tests/test_lottery.py F [100%]

============================================================================================= FAILURES ============================================================================================== ___ test_get_entrance_fee ___

def test_get_entrance_fee():
    account = accounts[0]
    lottery = Lottery.deploy(

      config["networks"][network.show_active()]["eth_usd_price_feed"],

{"from": account}, ) E KeyError: 'eth_usd_price_feed'

tests/test_lottery.py:8: KeyError ====================================================================================== short test summary info ====================================================================================== FAILED tests/test_lottery.py::test_get_entrance_fee - KeyError: 'eth_usd_price_feed' ========================================================================================= 1 failed in 1.31s ========================================================================================= Terminating local RPC client... joe@Joes-MacBook-Pro smartcontract-lottery %

[cromewar]

Do no forget to change the pyhton interpreter on vscode (bottom left corner) before opening it's terminal. If you are using the mac terminal you can refer to this: https://ahmadawais.com/how-to-set-python-default-version-to-3-on-macos/

[JMiddey]

This says I need homebrew but I've found it clashes with node, can i do without? (Thanks btw)

[cromewar]

Well you can uninstall node, and install it through brew, which is actually a good way no manage node packages as same as yarn.