solidity | Solidity , the Smart Contract Programming Language | Blockchain library

I used pip install eth-brownie and it worked fine, I didnt need to downgrade. Im new to this maybe I could be wrong but it worked fine with me.

These lines should be outside of the structs (Person, Company):

Had this issue myself, apparently it's some sort of Ganache CLI error but the simplest fix I could find was to change the network id in Ganache through settings>server to 1337. It restarts the session so you'd then need to change the address and private key variable.

If it's the same tutorial I'm doing, you're likely to come unstuck after this... the code for transaction should be:

That error is clear. you do not have sufficient funds. This is how you are getting the account information:

to test locally you need to make use of mocks which can simulate having an oracle network. Because you're working locally, a Chainlink node doesn't know about your local blockchain, so you can't actually do proper VRF requests. Note you can try deploy a local Chainlink node and a local blockchain and have them talk, but it isn't fully supported yet so you may get mixed results. Anyway, as per the hardhat starter kit that you linked, you can set the defaultNetwork to be 'hardhat' in the hardhat.config.js file, then when you deploy and run the integration tests (yarn test-integration), it will use mocks to mock up the VRF node, and to test the requesting of a random number. See the test here, and the mock contracts and linktoken get deployed here

Deploying a contract and interacting with the contract are two different things.

After you deployed the contract on a blockchain, then you need a provider which is kinda a bridge to a node in that blockchain.

This is fixed in Brownie v1.18.1. However, you will need to install Python 3.9.10 in order to get the latest brownie. For this to work in a virtual environment you can't use venv. Here is a process that works for me:

• install virtualenv on your standard Python version
• download python 3.9.10 and install it without "add to path" into a dedicated directory e.g. $home/pythonversions
• in your project directory create a virtual environment like so

python -m virtualenv -p=""

• start your virtual environment e.g. home>..venv\Scripts\activate.ps1

• test if your python version is the desired one with python --version

• Now install Cython to avoid another error.

• Install nodeenv in order to install ganage

• Activate with nodeenv -p (for this step you will need PowerShell with admin rights)

• Install ganache with npm

• Install eth-brownie with pip check if you got the latest version with

brownie --version

If you want to implement a defi contract (since your function name is addStaker) that accepts staked coins from ERC20 tokens, the implementation is different. But if you just want to send money to contract from your metamask account, you have to mark the function payable.

If you just want to access the functions, you can use either. But in interfaces you cannot have state variables so if you need some state variables you cast to contract.

Also interfaces cannot inherit other contracts or interfaces. Maybe the contract is inheriting from contractB and in your contract you want to access to contractB.