node.js - webpack-dev-server正常运行，webpack打包却出错，怎么办？

Question

一直在用webpack-dev-server开发，一切正常。结果在用webpack打包时却出错了。错误信息非常长，终端都显示不全。。。出错的路径都在node_modules中，错误信息基本是这两个：
Module not found: Error: Cannot resolve module 'fs' in xxxxxxx
和 You may need an appropriate loader to handle this file type.（载入json文件时）。
但是，运行webpack-dev-server却能够正常运行，并且和webpack打包时用的是同一个config文件。
不明白为什么直接用webpack打包会出错？请问问题出在哪呢？

Answer 1

Solved, it turns out that I accidentally put --progress between --config and webpack.prod.config.js. I just adjusted it. . . What a stupid mistake. . .

Answer 2

It should be that the dependent package is missing. Try reinstalling the package. If you see something missing, install it.