Populus: Contract fails due to solidity gas limit

Question

• platform darwin -- Python 2.7.12, pytest-3.0.2, py-1.4.31, pluggy-0.3.1
• plugins: populus==2.0.1
• OS: Mac OS X

I believe I face with this error due to Solidity compiler's default gas limit that is 3,000,000.

[Q] How could I increase my solidity compiler's gas limit due to this error, or another gas limit that populus reads from?

in estimate_gas -> does it exceed gas limit? When I remove some function inside my contract the error gets fixed. I guess there is a gas limit for populus to deploy the contract, is it possible to extend it? If yes how?

Error:

========================================== FAILURES ==========================================
________________________________________ test_receipt ________________________________________

web3 = <web3.main.Web3 object at 0x1061af2d0>
accounts = ['0x82A978B3f5962A5b0957d9ee9eEf472EE55B42F1', '0x7d577a597B2742b498Cb5Cf0C26cDCD726d39E6e', '0xDCEceAF3fc5C0a63d195d6...1d7585Bd0577402861E5', '0x13cBB8D99C6C4e0f2728C7d72606e78A29C4E224', '0x77dB2BEBBA79Db42a978F896968f4afCE746ea1F', ...]
chain = <populus.chain.tester.TesterChain object at 0x105489b50>

    def test_receipt(web3, accounts, chain): #{
        web3._requestManager = web3.manager
        global blkArrayIndex;
        global runTime;
>       my_contract, _   = chain.provider.get_or_deploy_contract('eBlocBroker');

tests/test.py:39:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
/Library/Python/2.7/site-packages/populus/contracts/provider.py:143: in get_or_deploy_contract
    deploy_kwargs=deploy_kwargs,
/Library/Python/2.7/site-packages/populus/contracts/provider.py:121: in deploy_contract
    kwargs=deploy_kwargs,
/Library/Python/2.7/site-packages/web3/contract.py:311: in deploy
    txn_hash = cls.web3.eth.sendTransaction(deploy_transaction)
/Library/Python/2.7/site-packages/web3/eth.py:216: in sendTransaction
    get_buffered_gas_estimate(self.web3, transaction),
/Library/Python/2.7/site-packages/web3/utils/transactions.py:28: in get_buffered_gas_estimate
    gas_estimate = web3.eth.estimateGas(gas_estimate_transaction)
/Library/Python/2.7/site-packages/web3/eth.py:263: in estimateGas
    [transaction],
/Library/Python/2.7/site-packages/web3/manager.py:93: in request_blocking
    response = self._make_request(method, params)
/Library/Python/2.7/site-packages/web3/manager.py:76: in _make_request
    return request_func(method, params)
/Library/Python/2.7/site-packages/web3/middleware/attrdict.py:20: in middleware
    response = make_request(method, params)
/Library/Python/2.7/site-packages/web3/middleware/formatting.py:23: in middleware
    response = make_request(method, formatted_params)
/Library/Python/2.7/site-packages/web3/middleware/formatting.py:25: in middleware
    response = make_request(method, params)
/Library/Python/2.7/site-packages/web3/middleware/exception_handling.py:20: in middleware
    return make_request(method, params)
/Library/Python/2.7/site-packages/web3/providers/tester.py:86: in middleware
    return make_request(method, params)
/Library/Python/2.7/site-packages/web3/providers/tester.py:115: in make_request
    response = rpc_fn(*params)
/Library/Python/2.7/site-packages/testrpc/rpc.py:138: in eth_estimateGas
    return self.client.estimate_gas(**formatted_transaction)
/Library/Python/2.7/site-packages/testrpc/client/client.py:253: in estimate_gas
    txn_hash = self.send_transaction(*args, **kwargs)
/Library/Python/2.7/site-packages/testrpc/client/client.py:263: in send_transaction
    self._send_transaction(*args, **kwargs)
/Library/Python/2.7/site-packages/testrpc/client/client.py:58: in inner
    return client_method(self, *args, **kwargs)
/Library/Python/2.7/site-packages/testrpc/client/utils.py:104: in inner
    return fn(*bytes_args, **bytes_kwargs)
/Library/Python/2.7/site-packages/testrpc/client/client.py:225: in _send_transaction
    output = self.evm.send(sender=sender, to=to, value=value, evmdata=data)
/Library/Python/2.7/site-packages/ethereum/tester.py:338: in send
    return self._send(*args, **kwargs)["output"]
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <ethereum.tester.state object at 0x1061af590>
sender = '\x04HR\xb2\xa6p\xad\xe5@~x\xfb(c\xc5\x1d\xe9\xfc\xb9eB\xa0q\x86\xfe:\xed\xa6\xbb\x8a\x11m'
to = '', value = 0
evmdata = "```@R4\x15a\x00\x0fW`\x00\x80\xfd[C`\x00\x81\x90UP3`\x01`\x00a\x01\x00\n\x81T\x81s\xff\xff\xff\xff\xff\xff\xff\xff\xf...c3V[P\x90V[\x90V\x00\xa1ebzzr0X Ks\x04pt'-\x02$\\\xbf\x86\x9c\x0f\xf8\xfa\xbf\x97\xda\xb8/\xd6X\xc8|\xadp\xc6JQpC\x00)"
funid = None, abi = None, profiling = 0

    def _send(self, sender, to, value, evmdata='', funid=None, abi=None,  # pylint: disable=too-many-arguments
              profiling=0):
        # pylint: disable=too-many-locals

        if funid is not None or abi is not None:
            raise Exception(
                'Send with funid+abi is deprecated. Please use the abi_contract mechanism'
            )

        start_time = time.time()
        gas_used = self.block.gas_used

        sendnonce = self.block.get_nonce(privtoaddr(sender))
        transaction = transactions.Transaction(sendnonce, gas_price, gas_limit, to, value, evmdata)
        self.last_tx = transaction
        transaction.sign(sender)
        recorder = None

        if profiling > 1:
            recorder = LogRecorder(
                disable_other_handlers=True,
                log_config=TRACE_LVL_MAP[3],
            )

        try:
            (success, output) = processblock.apply_transaction(self.block, transaction)

            if not success:
>               raise TransactionFailed()
E               TransactionFailed

/Library/Python/2.7/site-packages/ethereum/tester.py:296: TransactionFailed
------------------------------------- Captured log call --------------------------------------
rpc.py                     129 INFO     eth_blockNumber
============================ 1 failed, 4 warnings in 1.41 seconds ============================

---

Update:

The way I use Populus:

$ mkdir populus_workspace && cd populus_workspace
$ [~/populus_workspace] populus init
Created Directory: ./contracts
Created Example Contract: ./contracts/Greeter.sol
Created Directory: ./tests
Created Example Tests: ./tests/test_greeter.py
$ py.test --capture=fd tests/test_greeter.py -s --disable-pytest-warnings
==================================== test session starts =====================================
platform darwin -- Python 2.7.10, pytest-3.5.0, py-1.5.3, pluggy-0.6.0
rootdir: /Users/alper/mu, inifile:
plugins: populus-2.0.1
collected 2 items

tests/test_greeter.py ..

============================ 2 passed, 6 warnings in 0.82 seconds ============================

Based on @mafrasi2 answer when I tried:

 my_contract, _   = chain.provider.get_or_deploy_contract('eBlocBroker', deploy_transaction={"gas": 4000001})

I get following error message:

block = <Block(#1 2bb28319)>, tx = <Transaction(751d)>

    def validate_transaction(block, tx):

        def rp(what, actual, target):
            return '%r: %r actual:%r target:%r' % (tx, what, actual, target)

        # (1) The transaction signature is valid;
        if not tx.sender:  # sender is set and validated on Transaction initialization
            if block.number >= config.default_config["METROPOLIS_FORK_BLKNUM"]:
                tx._sender = normalize_address(config.default_config["METROPOLIS_ENTRY_POINT"])
            else:
                raise UnsignedTransaction(tx)
        if block.number >= config.default_config["HOMESTEAD_FORK_BLKNUM"]:
                tx.check_low_s()

        # (2) the transaction nonce is valid (equivalent to the
        #     sender account's current nonce);
        acctnonce = block.get_nonce(tx.sender)
        if acctnonce != tx.nonce:
            raise InvalidNonce(rp('nonce', tx.nonce, acctnonce))

        # (3) the gas limit is no smaller than the intrinsic gas,
        # g0, used by the transaction;
        if tx.startgas < tx.intrinsic_gas_used:
            raise InsufficientStartGas(rp('startgas', tx.startgas, tx.intrinsic_gas_used))

        # (4) the sender account balance contains at least the
        # cost, v0, required in up-front payment.
        total_cost = tx.value + tx.gasprice * tx.startgas
        if block.get_balance(tx.sender) < total_cost:
            raise InsufficientBalance(rp('balance', block.get_balance(tx.sender), total_cost))

        # check block gas limit
        if block.gas_used + tx.startgas > block.gas_limit:
>           raise BlockGasLimitReached(rp('gaslimit', block.gas_used + tx.startgas, block.gas_limit))
E           BlockGasLimitReached: <Transaction(751d)>: 'gaslimit' actual:4000001 target:4000000

/Library/Python/2.7/site-packages/ethereum/processblock.py:112: BlockGasLimitReached

Answer 1

Unfortuately, you can't do this on the command line right now. However, Populus also allows you to use a script to deploy your contract which gives you a ton of customization.

The example in the documentation uses the default gas amount:

txhash = Crowdsale.deploy(
    transaction={"from": beneficiary},
    args=[beneficiary, multisig_address, 1]
)

You can simply change this by adding "gas": x to the transaction parameter:

txhash = Crowdsale.deploy(
    transaction={"from": beneficiary, "gas": 4000000},
    args=[beneficiary, multisig_address, 1]
)

In general, you can use all the functionality from web3py in Populus. There even is functionality to automatically estimate the amount of gas needed beforehand:

gas_needed = Crowdsale.constructor(beneficiary, multisig_address, 1).estimateGas()

Edit:

I think your problem occurs when you call get_or_deploy_contract()? In that case, you can use:

chain.provider.get_or_deploy_contract('eBlocBroker', deploy_transaction={"gas": 4000000})

Edit 2:

After going through lots of code, I have some new information. Populus uses its tester chain by default. The tester chain represents EthereumTesterProvider from web3py. Now, there are two versions of EthereumTesterProvider: one uses eth-tester and the other uses eth-testrpc. The second one is deprecated, but it's the one that Populus uses. Now, there are two ways to set the block gas limit in eth-testrpc:

• either, set the environment variable TESTRPC_GAS_LIMIT to something very high like 8000000 before you call py.test ...

• or, put this snippet into your test_*.py file:

  import pytest
  
  @pytest.fixture(scope="session", autouse=True)
  def adjust_block_gas_limit():
      import testrpc.client
      testrpc.client.client.DEFAULT_GAS_LIMIT = 8000000
  

Answer 2

Based on @mafrasi2 answer changing the value inside test_*.py file did not help.

---

By default DEFAULT_GAS_LIMIT is assigned with 4000000.

Please see eth-testrpc/testrpc/client/client.py :

DEFAULT_GAS_LIMIT = t.gas_limit = t.GAS_LIMIT = int(os.environ.get('TESTRPC_GAS_LIMIT', 4000000))

We need to increase DEFAULT_GAS_LIMIT value.

$ pip show eth-testrpc | grep 'Location'
Location: /Library/Python/2.7/site-packages
$ cd /Library/Python/2.7/site-packages
$ grep -r 'TESTRPC_GAS_LIMIT' .
./testrpc/client/client.py:DEFAULT_GAS_LIMIT = t.gas_limit = t.GAS_LIMIT = int(os.environ.get('TESTRPC_GAS_LIMIT', 4000000))

Then open ./testrpc/client/client.py with your editor and update 4000000 with a larger value.

---

Example test.py: (To run: py.test --capture=fd test.py -s --disable-pytest-warnings)

import pytest
def test_receipt(web3, accounts, chain): #{    
    my_contract, _   = chain.provider.get_or_deploy_contract('myContractName');
    ...
#}