reactjs - React-create-app 中 babel loader 的问题

Question

问题

create-react-app 初始化一个存储库，其中 babel-loader 安装为比需要的旧版本。

日志:

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-loader": "8.0.4"

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

  C:\Users\user\node_modules\babel-loader (version: 8.0.2)

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-loader" 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 C:\Users\User\node_modules\babel-loader is outside your project directory.
         For example, you might have accidentally installed something in your home folder.

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

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

    npm ERR! A complete log of this run can be found in:
    npm ERR!     C:\Users\User\AppData\Roaming\npm-cache\_logs\2018-12-13T18_22_47_802Z-debug.log

事情发生后

$ npx create-react-app reg && cd reg && npm start

我尝试过的

我尝试删除 node_modules 文件夹和 package-lock.json，然后运行 ​​npm install。

还安装了yarn并运行yarn &&yarn start。

我已重新创建该应用 3 次，但得到了相同的结果。

可能有帮助的信息

节点版本:10.8.0
NPM版本:6.5.0
创建 react 应用程序/ react 脚本:2.1.1
babel-loader:8.0.4
全局包列表(npm ls --depth=0 -g):

+-- create-react-app@2.1.1
+-- node-gyp@3.6.2
+-- npm@6.5.0
+-- yarn@1.12.3

package.json 文件:

{
  "name": "reg",
  "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

遇到同样的问题，但花了一个小时得到解决方案当我们运行 npm start 时，您会收到此类错误，该错误是与此问题的版本相关的问题。转到node_modules文件夹:

Project->node_modules->react-scripts->package.json

检查package.json文件

你得到了:“babel-loader”:“8.0.4”首先删除: Project->node_modules->babel-loader 的 babel-loader 文件夹然后运行 ​​npm i babel-loader@8.0.4 (这取决于你的版本，你可以像这样更改它:npm i babel-loader@8.0.5)之后可能会遇到 webpack 问题然后按照同样的方式从“Project->node_modules->webpack”中移除 webpack并重新安装npm i webpack@4.19.1

4.19.1* webpack 的版本可能会改变..