在使用 Npm start 启动项目期间项目中出现错误，使用 create-react-app 创建项目

Question

我使用的是 ubantu 16 操作系统并且我已经安装了

节点版本 v10.13.0 和 npm 版本 6.4.1

我正在创建基于create-react-app 的 Reactjs 项目。

我已经使用命令创建了项目

sudo npm init react-app my-app

这个命令成功创建了我的应用程序，但是当我使用 npm start 运行项目时 我的应用程序文件夹下的命令我收到以下错误

> my-app@0.1.0 start /home/karan/workspace/1425/my-app
> react-scripts start


There might be a problem with the project dependency tree. It is likely not a bug in Create React App, but something you need to fix locally.

The react-scripts package provided by Create React App requires a dependency:

  "babel-jest": "23.6.0"

Don't try to install it manually: your package manager does it automatically. However, a different version of babel-jest was detected higher up in the tree:

  /home/karan/workspace/node_modules/babel-jest (version: 22.4.4) 

Manually installing incompatible versions is known to cause hard-to-debug issues.

If prefer to ignore this check, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project. That will permanently disable this message but you might encounter other issues.

To fix the dependency tree, try following the steps below in the exact order:

  1. Delete package-lock.json (not package.json!) and/or yarn.lock in your project folder.
  2. Delete node_modules in your project folder.
  3. Remove "babel-jest" from dependencies and/or devDependencies in the package.json file in your project folder.
  4. Run npm install or yarn, depending on the package manager you use.

In most cases, this should be enough to fix the problem. If this has not helped, there are a few other things you can try:

  5. If you used npm, install yarn (http://yarnpkg.com/) and repeat the above steps with it instead.
     This may help because npm has known issues with package hoisting which may get resolved in future versions.

  6. Check if /home/karan/workspace/node_modules/babel-jest is outside your project directory.
     For example, you might have accidentally installed something in your home folder.

  7. Try running npm ls babel-jest in your project folder.
     This will tell you which other package (apart from the expected react-scripts) installed babel-jest.

If nothing else helps, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project. That would permanently disable this preflight check in case you want to proceed anyway.

P.S. We know this message is long but please read the steps above :-) We hope you find them helpful!

npm ERR! code ELIFECYCLE npm ERR! errno 1 npm ERR! my-app@0.1.0 start: `react-scripts start` npm ERR! Exit status 1 npm ERR!  npm ERR! Failed at the my-app@0.1.0 start script. npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

因为这显示了相关的问题

react-scripts start ,"babel-jest": "23.6.0"

但我是 js 框架（node/npm/react）的新手，请问这个问题将如何解决？

package.json

{
  "name": "my-app",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "react": "^16.6.3",
    "react-dom": "^16.6.3",
    "react-scripts": "2.1.1"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": [
    ">0.2%",
    "not dead",
    "not ie <= 11",
    "not op_mini all"
  ]
}

Answer 1

即使您收到的是ELIFECYCLE 错误而不是EACCES，也可能与您使用sudo 运行命令有关。尝试再次创建并运行项目，不使用 sudo。

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