Error compiling OpenZeppelin imported contracts in truffle in vs code


I’m running a truffle project created with truffle init command in CMD. then I create a react app with npx reate-react-app in the same folder.
I’m creating a NFT so I have installed OZ contracts in my react app with using npm install @openzeppelin/contracts command.

Now at this point whole project looks like this.

root folder

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and this is the complete truffle-config.js

 * Use this file to configure your truffle project. It's seeded with some
 * common settings for different networks and features like migrations,
 * compilation and testing. Uncomment the ones you need or modify
 * them to suit your project as necessary.
 * More information about configuration can be found at:
 * To deploy via Infura you'll need a wallet provider (like @truffle/hdwallet-provider)
 * to sign your transactions before they're sent to a remote public node. Infura accounts
 * are available for free at:
 * You'll also need a mnemonic - the twelve word phrase the wallet uses to generate
 * public/private key pairs. If you're publishing your code to GitHub make sure you load this
 * phrase from a file you've .gitignored so it doesn't accidentally become public.

// const HDWalletProvider = require('@truffle/hdwallet-provider');
// const infuraKey = "fj4jll3k.....";
// const fs = require('fs');
// const mnemonic = fs.readFileSync(".secret").toString().trim();
const path = require("path");
module.exports = {
  contracts_build_directory: path.join(__dirname, "client/src/contracts"),
   * Networks define how you connect to your ethereum client and let you set the
   * defaults web3 uses to send transactions. If you don't specify one truffle
   * will spin up a development blockchain for you on port 9545 when you
   * run `develop` or `test`. You can ask a truffle command to use a specific
   * network from the command line, e.g
   * $ truffle test --network <network-name>

  networks: {
    // Useful for testing. The `development` name is special - truffle uses it by default
    // if it's defined here and no other network is specified at the command line.
    // You should run a client (like ganache-cli, geth or parity) in a separate terminal
    // tab if you use this network and you must also set the `host`, `port` and `network_id`
    // options below to some value.
     development: {
      host: "",     // Localhost (default: none)
      port: 7545,            // Standard Ethereum port (default: none)
      network_id: "*",       // Any network (default: none)
    // Another network with more advanced options...
    // advanced: {
    // port: 8777,             // Custom port
    // network_id: 1342,       // Custom network
    // gas: 8500000,           // Gas sent with each transaction (default: ~6700000)
    // gasPrice: 20000000000,  // 20 gwei (in wei) (default: 100 gwei)
    // from: <address>,        // Account to send txs from (default: accounts[0])
    // websocket: true        // Enable EventEmitter interface for web3 (default: false)
    // },
    // Useful for deploying to a public network.
    // NB: It's important to wrap the provider as a function.
    // ropsten: {
    // provider: () => new HDWalletProvider(mnemonic, ``),
    // network_id: 3,       // Ropsten's id
    // gas: 5500000,        // Ropsten has a lower block limit than mainnet
    // confirmations: 2,    // # of confs to wait between deployments. (default: 0)
    // timeoutBlocks: 200,  // # of blocks before a deployment times out  (minimum/default: 50)
    // skipDryRun: true     // Skip dry run before migrations? (default: false for public nets )
    // },
    // Useful for private networks
    // private: {
    // provider: () => new HDWalletProvider(mnemonic, ``),
    // network_id: 2111,   // This network is yours, in the cloud.
    // production: true    // Treats this network as if it was a public net. (default: false)
    // }

  // Set default mocha options here, use special reporters etc.
  mocha: {
    // timeout: 100000

  // Configure your compilers
  compilers: {
    solc: {
       version: "0.6.1",    // Fetch exact version from solc-bin (default: truffle's version)
      // docker: true,        // Use "0.5.1" you've installed locally with docker (default: false)
      // settings: {          // See the solidity docs for advice about optimization and evmVersion
      //  optimizer: {
      //    enabled: false,
      //    runs: 200
      //  },
      //  evmVersion: "byzantium"
      // }

  // Truffle DB is currently disabled by default; to enable it, change enabled: false to enabled: true
  // Note: if you migrated your contracts prior to enabling this field in your Truffle project and want
  // those previously migrated contracts available in the .db directory, you will need to run the following:
  // $ truffle migrate --reset --compile-all

  db: {
    enabled: false

in my solidity contract file, path is C:DappPet-Shop-IPFS-ReactcontractsPetShop.sol, I’ve imported the installed OZ ERC721 contract

pragma solidity >=0.4.22 <0.9.0;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";

contract PetShop is ERC721 {
      uint256 public tokenId;
      uint256 public prevOwnerTokenID;
      address public owner;
      mapping(uint256 => uint256) public priceMapping;
      mapping(uint256 => string) tokenIdToOffchainContentHash;
      event PetGenerated(address, uint256, uint256, string);
      event BuyPet(uint256, address, address);
      event SuccessfulEtherWithdrawal(uint256, address, bool);
        ERC721("ShanBuilders", "SBRS")
            owner = msg.sender;
       function generatePet(uint256 _petPrice, string memory contentHash) public returns(bool) {
         require(msg.sender != address(0), "Please! Check back! Registeration should not be from zero address");
         require(msg.sender == owner, "Only contract owner can generate more pets");
         require(tokenId <= 16, "More than 16 pets is not allowed");
         priceMapping[tokenId] = _petPrice;
         tokenIdToOffchainContentHash[tokenId] = contentHash;
         _mint(owner, tokenId);
         emit PetGenerated(owner, tokenId, _petPrice, contentHash);
         return true;
       function checkPrice(uint256 _tokenId) public view returns(uint256) {
           return priceMapping[_tokenId];
       function checkHashForAToken(uint256 _tokenId) public view returns(string memory) {
           return tokenIdToOffchainContentHash[_tokenId];
       function buyPet(uint256 _tokenId) public payable returns(bool, string memory) {
           prevOwnerTokenID = _tokenId;
           address buyer = msg.sender;
           address _owner = ownerOf(prevOwnerTokenID);
           require(buyer != address(0), "Should not be zero address");
           require(_exists(prevOwnerTokenID), "Invalid property Id, not registered");
           require(msg.value == checkPrice(prevOwnerTokenID), "Please Send The Required Value");
            _transfer(_owner, buyer, prevOwnerTokenID);
           emit BuyPet(_tokenId, _owner, buyer);
           return (true, "Succesful");
       function withDraw(uint256 _amount) internal returns(bool) {
        address _owner = ownerOf(prevOwnerTokenID);
        require(_amount > 0, "Amount must be valid");
        emit SuccessfulEtherWithdrawal(_amount, _owner, true);
        return true;

this is Migration

const PetShop = artifacts.require("PetShop");

module.exports = function (deployer) {

Q is after doing all this something went wrong that I didn’t notice. when i run truffle compile it fails the compilation and throws error,
enter image description here

*** ParserError: Source "@openzeppelin/contracts/token/ERC721/ERC721.sol" not found: File import callback not supported***

How can I work around this issue, It will be great if someone could help me understand what this error says and why this is happening?

Source: Visual Studio Questions

One Reply to “Error compiling OpenZeppelin imported contracts in truffle in vs code”

  • Same problem here, I’ve read that it could be a problem occuring when compiling using Windows.
    I also tried whit Ubuntu but I have the same problem.
    If I find a solution I’ll text you back