contract deploy function returns `brownie.exceptions.VirtualMachineError: revert`

Environment information

• brownie Version: 1.14.6
• ganache-cli Version: 6.12.2
• vyper Version: 0.2.12+commit.2c6842c
• Python Version: 3.9.4
• OS: osx

What was wrong?

in my conftest.py file i have:

import pytest
import brownie
from brownie import accounts, contract_name

# deploy contract
@pytest.fixture(scope="module")
def deploy(contract_name, accounts):
    return contract_name.deploy({'from':accounts[0]}) # yes, the contract constructor takes no args

# clean chain for each function, ensures clean working environment
@pytest.fixture(autouse=True)
def shared_setup(fn_isolation):
    pass

and then in my tests/some_test_file.py i have:

import pytest
import brownie
from brownie import accounts
from brownie.test import given, strategy

@given(amount_sent = strategy('uint256', max_value=10**18, min_value=2))
def test_tax_amount_deducted_from_party_balances(amount_sent, deploy):
    # do stuff

running brownie test tests/some_test_file.py or any test for that matter returns this error:

Brownie v1.14.6 - Python development framework for Ethereum

======================================================== test session starts ========================================================
platform darwin -- Python 3.9.4, pytest-6.2.3, py-1.10.0, pluggy-0.13.1
rootdir: /Users/REDACTED/Desktop/file/another_file
plugins: eth-brownie-1.14.6, hypothesis-6.10.0, xdist-1.34.0, forked-1.3.0, web3-5.18.0
collected 1 item                                                                                                                    

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

tests/test_tax.py E                                                                                                           [100%]

============================================================== ERRORS ===============================================================
__________________________________ ERROR at setup of test_tax_amount_deducted_from_party_balances ___________________________________

contract_name = <brownie.network.contract.ContractContainer object at 0x7ffbcdc44c10>
accounts = <brownie.network.account.Accounts object at 0x7ffbcb881880>

    @pytest.fixture(scope="module")
    def deploy(contract_name, accounts):
>       return contract_name.deploy({'from':accounts[0]})
E       brownie.exceptions.VirtualMachineError: revert

tests/conftest.py:8: VirtualMachineError
====================================================== short test summary info ======================================================
ERROR tests/test_tax.py::test_tax_amount_deducted_from_party_balances - brownie.exceptions.VirtualMachineError: revert
========================================================= 1 error in 10.91s =========================================================
Terminating local RPC client...

odd because it was working before i put it into the conftest, but moving it back to the individual test file makes no difference so not the cause

thanks in advance for the help, brownie is awesome i much prefer it to truffle

[liam-ot]

@skellet0r actually, you made a good point that there was an assumption in the constructor, I was attempting to set a variable in the contract with an interface call, commenting out lead to a different issue, but the issue described here is fixed, thanks

[liam-ot]

output from deploying with contract_name.deploy({'from':accounts[0]})

Transaction sent: 0xd6c0358295c9d9adbc8855c01c06922ef009f0979b59b9d47d22d3dbe10fb5c0
  Gas price: 0.0 gwei   Gas limit: 12000000   Nonce: 0
  new_metawhale.constructor confirmed (reverted) - Block: 1   Gas used: 261099 (2.18%)

<Transaction '0xd6c0358295c9d9adbc8855c01c06922ef009f0979b59b9d47d22d3dbe10fb5c0'>