webpack-dev-server无法运行，并发生validateSchema错误

Question

this is a react hello-world proj , on local machine win7, use npm download packages, when run " webpack-dev-server --open " it has an error like these:

 F:\\now\\react\\setup\\node_modules\\webpack-cli\\bin\\convert-argv.js:7 const validateSchema = process.webpackModule.validateSchema; TypeError: Cannot read property 'validateSchema' of undefined ... 

screenshot about error info

this is the package.json and webpack.config.js

 { "name": "setup", "version": "1.0.0", "description": "", "main": "index.js", "scripts": { "test": "echo \\"Error: no test specified\\" && exit 1", "start": "webpack-dev-server --open" }, "author": "", "license": "ISC", "dependencies": {}, "devDependencies": { "babel-core": "^6.26.3", "babel-loader": "^7.1.4", "babel-preset-env": "^1.7.0", "babel-preset-react": "^6.24.1", "react": "^16.4.0", "react-dom": "^16.4.0", "webpack": "^4.10.2", "webpack-cli": "^3.0.0", "webpack-dev-server": "^3.1.4" } } 

webpack.config.js:

 const webpack = require('webpack'); module.exports = { devServer: { contentBase: "./src", historyApiFallback: true, inline: true }, module: { rules: [ { test: /(\\.jsx|\\.js)$/, use: { loader: "babel-loader", options: { presets: [ "env", "react" ] } }, exclude: /node_modules/ } ] } } 

Answer 1

The webpack-cli just bumped from v2 to v3 about 10 hours ago, and it looks like this might be a bug with v3. I haven't figured out an actual fix yet, but a temporary workaround is to downgrade to webpack-cli v2 by manually changing the version number in your package.json to ^2.0.0 .

Hope that helps you get unstuck for the moment.