导入API_URL和私钥时出现Hardhat编译错误

Question

为了遵循一个基本的NFT tutorial，我不得不说，我在编程方面是一个新手。我面临的问题是，我的hardhat.config.js文件需要一个API_KEY和一个私钥，它应该从process.env文件中导入：

API_URL = "https://ethropsten.alchemyapi.io/v2/UkW3oySI7WxvFwDwopQHPOHajHaWFZFv"
PRIVATE_KEY = "8d33c2613cb63d0dc6305e57..."

硬配置文件如下所示：

* @type import('hardhat/config').HardhatUserConfig
*/
require('dotenv').config();
require("@nomiclabs/hardhat-ethers");
const { API_URL, PRIVATE_KEY } = process.env;
module.exports = {
  solidity: "0.8.0",
  defaultNetwork: "ropsten",
  networks: {
    hardhat: {},
    ropsten: {
      url: API_URL,
      accounts: [`0x${PRIVATE_KEY}`]
    }
  },
} 

但是每当我试图编译它并通过我的deploy.js文件运行它时，我得到一个错误消息，基本上告诉我，导入是不可能的，看起来是这样的：

  * Invalid value undefined for HardhatConfig.networks.ropsten.url - Expected a value of type string.
  * Invalid value {"accounts":["0xundefined"]} for HardhatConfig.networks.ropsten - Expected a value of type HttpNetworkConfig.
  
To learn more about Hardhat's configuration, please go to https://hardhat.org/config/

For more info go to https://hardhat.org/HH8 or run Hardhat with --show-stack-traces
simon@MacBook-Pro-von-Simon test_fractals % npx hardhat run scripts/deploy.js --network ropsten
An unexpected error occurred:

simon@MacBook-Pro-von-Simon test_fractals % npx hardhat run scripts/deploy.js --network ropsten
An unexpected error occurred:

simon@MacBook-Pro-von-Simon test_fractals % npx hardhat run scripts/deploy.js --network ropsten
An unexpected error occurred:

ReferenceError: API_KEY is not defined
    at Object.<anonymous> (/Users/simon/test_fractals/hardhat.config.js:37:12)
    at Module._compile (internal/modules/cjs/loader.js:1072:14)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1101:10)
    at Module.load (internal/modules/cjs/loader.js:937:32)
    at Function.Module._load (internal/modules/cjs/loader.js:778:12)
    at Module.require (internal/modules/cjs/loader.js:961:19)
    at require (internal/modules/cjs/helpers.js:92:18)
    at importCsjOrEsModule (/Users/simon/test_fractals/node_modules/hardhat/src/internal/core/config/config-loading.ts:23:20)
    at Object.loadConfigAndTasks (/Users/simon/test_fractals/node_modules/hardhat/src/internal/core/config/config-loading.ts:66:18)
    at main (/Users/simon/test_fractals/node_modules/hardhat/src/internal/cli/cli.ts:129:20)
simon@MacBook-Pro-von-Simon test_fractals % npx hardhat run scripts/deploy.js --network ropsten
An unexpected error occurred:

ReferenceError: API_KEY is not defined
    at Object.<anonymous> (/Users/simon/test_fractals/hardhat.config.js:37:12)
    at Module._compile (internal/modules/cjs/loader.js:1072:14)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1101:10)
    at Module.load (internal/modules/cjs/loader.js:937:32)
    at Function.Module._load (internal/modules/cjs/loader.js:778:12)
    at Module.require (internal/modules/cjs/loader.js:961:19)
    at require (internal/modules/cjs/helpers.js:92:18)
    at importCsjOrEsModule (/Users/simon/test_fractals/node_modules/hardhat/src/internal/core/config/config-loading.ts:23:20)
    at Object.loadConfigAndTasks (/Users/simon/test_fractals/node_modules/hardhat/src/internal/core/config/config-loading.ts:66:1 

我首先想到的是，我的.env文件不在正确的位置，或者语法不正确，但是在尝试了所有我能想到的东西之后，我仍然得到相同的错误消息。任何帮助都是非常感谢的。

Answer 1

我在hardhat.config.js文件中使用下面的代码解决了同样的问题：

require('dotenv').config({path:__dirname+'/.env'})

而不是：

require('dotenv').config()

欲了解更多信息，请访问dotenv file is not loading environment variables