在默认本地 ganache 上部署时，Brownie ParserError openzeppelin/contracts/token/ERC20/ERC20.sol

Question

ParserError: Source "@openzeppelin/contracts/token/ERC20/ERC20.sol" not found: File not found.

While I'm deploying with brownie on default local ganache-cli.

Command:

$ brownie compile

gets:

Brownie v1.17.2 - Python development framework for Ethereum

Compiling contracts...
  Solc version: 0.8.11
  Optimizer: Enabled  Runs: 200
  EVM Version: Istanbul
CompilerError: solc returned the following errors:

ParserError: Source "@openzeppelin/contracts/token/ERC20/ERC20.sol" not found: File not found.

Token file head:

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract InvestToken is ERC20 {

brownie-config.yaml file:

dependencies:
  # - <organization/repo>@<version>
  - OpenZeppelin/openzeppelin-contracts@4.4.2
compiler:
  solc:
    remappings:
      - '@openzeppelin = OpenZeppelin/openzeppelin-contracts@4.4.2'

command:

$brownie pm install OpenZeppelin/openzeppelin-contracts@4.4.2

gets:

FileExistsError("Package is aleady installed")

Answer 1

I made a mistake in the brownie-config.yaml file:

I wrote:

remappings:
      - '@openzeppelin = OpenZeppelin/openzeppelin-contracts@4.4.2'

and it is

remappings:
      - '@openzeppelin=OpenZeppelin/openzeppelin-contracts@4.4.2'

sorry about that

Answer 2

Base on your error I think is relate with brownie-config.yaml when new line don't use tab, use space

my issue with brownie-config.yaml

dependencies: 
  - OpenZeppelin/openzeppelin-contracts@4.2.0
compiler: 
  solc: 
    ramappings: 
      - '@openzeppelin=OpenZeppelin/openzeppelin-contracts@4.2.0'
dotenv: .env
wallets: 
  from_key: ${PRIVATE_KEY}

when I fixed form tab to space

dependencies:
 - OpenZeppelin/openzeppelin-contracts@4.2.0
compiler:
 solc:
  remappings:
    - '@openzeppelin=OpenZeppelin/openzeppelin-contracts@4.2.0'
dotenv: .env
wallets:
  from_key: ${PRIVATE_KEY}

also u can check ref from Patrick:

Answer 3

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openzeppelin-contracts/contracts/token/ERC20/ERC20.sol

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// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/ERC20.sol) pragma solidity ^0.8.0; import "./IERC20.sol";import "./extensions/IERC20Metadata.sol";import "../../utils/Context.sol"; /** * @dev Implementation of the {IERC20} interface. * * This implementation is agnostic to the way tokens are created. This means * that a supply mechanism has to be added in a derived contract using { mint}. * For a generic mechanism see {ERC20PresetMinterPauser}. * * TIP: For a detailed writeup see our guide * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How * to implement supply mechanisms]. * * We have followed general OpenZeppelin Contracts guidelines: functions revert * instead returning false on failure. This behavior is nonetheless * conventional and does not conflict with the expectations of ERC20 * applications. * * Additionally, an {Approval} event is emitted on calls to {transferFrom}. * This allows applications to reconstruct the allowance for all accounts just * by listening to said events. Other implementations of the EIP may not emit * these events, as it isn't required by the specification. * * Finally, the non-standard {decreaseAllowance} and {increaseAllowance} * functions have been added to mitigate the well-known issues around setting * allowances. See {IERC20-approve}. /contract ERC20 is Context, IERC20, IERC20Metadata { mapping(address => uint256) private _balances; mapping(address => mapping(address => uint256)) private _allowances; uint256 private _totalSupply; string private _name; string private _symbol; / * * @dev Sets the values for {name} and {symbol}. * * The default value of {decimals} is 18. To select a different value for * {decimals} you should overload it. * * All two of these values are immutable: they can only be set once during * construction. */ constructor(string memory name , string memory symbol_) { name = name ; symbol = symbol ; } /** * @dev Returns the name of the token. */ function name() public view virtual override returns (string memory) { return _name; }