npm start 运行'webpack-dev-server'报错 Cannot find module 'webpack'

Question

运行 cnpm start 运行"webpack-dev-server " 后报错：没有找到webpack。
packge.json文件内容如下：

{
      "name": "test",
      "version": "1.0.0",
      "description": "",
      "main": "index.js",
      "scripts": {
        "start": "webpack-dev-server "
      },
      "author": "",
      "license": "ISC",
      "dependencies": {
        "webpack-dev-server": "^2.4.5"
      }
  }

webpack.config.js:

运行 ：
报错：

我全局安装的webpack 不知道为什么会报找不到webpack。
但是自己手动输入 'webpack-dev-server'
运行成功:

希望知道是什么原因

Answer 1

试下npm run start

Answer 2

webpack.config.js里使用了webpack，所以webpack也需局部安装（本项目）依赖；