Lesson 4: Deploying via Infura

[semsion]

Having tested everything as working fine locally using Ganache, I then went on to test on the Rinkeby test network via Infura (from 4h23m2s https://youtu.be/M576WGiDBdQ?t=15782)

The problem is every time I've run the deploy.py script I get some kind of exception, apart from once, and on this occasion the amount stored via the 'store' function call didn't work, and the returned value was zero (this was returning as 15 locally).

Some of the exceptions I've been getting:

• Could not decode contract function call to retrieve with return data: b'', output_types: ['uint256']
• ValueError: {'code': -32000, 'message': 'replacement transaction underpriced'}
• web3.exceptions.TimeExhausted: Transaction HexBytes('0x9c052b9c907e9540ef064a074a1c61a625dae69e888b58ca9b609b799f8a0fee') is not in the chain, after 120 seconds

Can anyone please clarify why these exceptions and incorrect function call returns might be happening?

UPDATE:

Interestingly, earlier on in the video Patrick added a ‘returns (uint256)’, and ‘return favoriteNumber’ to the SimpleStorage.sol contract. I removed these (as per the version in github), and deploy.py ran as expected for the first time.

Subsequent runs started rendering similar timeout errors though, and also came back with a new error:

• web3.exceptions.BadFunctionCallOutput: Could not transact with/call contract function, is contract deployed correctly and chain synced?

Any help gratefully received...

[cromewar]

Hello @semsion I will try to solve your question:

Could not decode contract function call to retrieve with return data: b'', output_types: ['uint256']:

Make sure the function retrieve on your SimpleStorage.sol has a return value uint256:

function retrieve() public view returns (uint256){
        return favoriteNumber;
    }

Also in the store function:

function store(uint256 _favoriteNumber) public {
      favoriteNumber = _favoriteNumber;
  }

ValueError: {'code': -32000, 'message': 'replacement transaction underpriced'}

First of all make sure you have enough ETH on your Rinkeby wallet, you can get it from the new faucet provided by chainlink: https://faucets.chain.link/rinkeby

Well the problem occurs because web3 thinks you want to replace an existing uncompleted transaction and it could be solved in different ways.

Easiest one: just delete the compiled_code.json and compile again.
Set the nonce higher: this will say web3 that you are doing a new transaction so:

nonce = w3.eth.getTransactionCount(my_address) + 20 for example

Increase the gas price: this one is more complex to do and is not worth.

web3.exceptions.TimeExhausted: Transaction HexBytes('0x9c052b9c907e9540ef064a074a1c61a625dae69e888b58ca9b609b799f8a0fee') is not in the chain, after 120 seconds

this is related to the last problem, as the transaction is never completed the default timeout raises the exception.

[semsion]

I was getting an error inside vscode stating that brownie could not be imported. I than ran ‘pip3 list’ to see what was installed, and could see that brownie wasn't, despite following the instructions. I ran ‘pip3 install eth-brownie’ and vscode could then see the module.

I was under the impression using pip would use pip3, but it appears not. Maybe this has caused other issues elsewhere.

[cromewar]

Interesting enough some windows users had the same problems installing brownie with pipx, as vscode was incapable of recognize brownie.

• make sure you have selected the correct python interpreter on vscode.
• try installing brownie with pipx
• restart vscode may help

[semsion]

I went back and tried the web3_py_simple_storage project again after uninstall (pip and pip3) and reinstall (pip3) of web3, py-solc-x, etc. Still getting a timeout error.

I'm moving on with the brownie_simple_storage section now.

As I say the brownie import appears fine after installing with pip3.

[cromewar]

I've been doing research on the timeout you have, I've reproduced the code on PopOs 21.04 which is basically Ubuntu and I wasn't able to reproduce the problem as everything worked fine on the first run.

Let us know if you have more questions with the following sections.

Best regards, Cromewar

[semsion]

Hmm, okay - many thanks for testing.

The first run has sometimes worked, with subsequent runs timing out or returning errors.

Anyway, I'll see how I get on going forward...

[mjh-jhm]

It seems the retrieve() function has to have an additional bool return value

I fixed it by updating the function as followed:

    function retrieve() public view returns (bool _b, uint256) {
        return (_b, favoriteNumber);
    }

The boolean returns false as the function itself is not TransactionReceipt.

[cromewar]

Nice, does this work for you @semsion ?

[fantauzzi]

Got a "ValueError: replacement transaction underpriced" error when running the integration test test_can_pick_winner on Rinkeby, deleting the content of the build directory fixed it.