【npm】npm install命令报错npm ERR! code ERESOLVE npm ERR! ERESOLVE unable to resolve dependency tree

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一、现象：

npm ERR! code ERESOLVE npm ERR! ERESOLVE unable to resolve dependency tree

npm ERR! code ERESOLVE npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR! 
npm ERR! Found: [email protected]
npm ERR! node_modules/webpack
npm ERR!   dev webpack@"4.41.5" from the root project
npm ERR!   peer webpack@">=2" from [email protected]
npm ERR!   node_modules/babel-loader
npm ERR!     dev babel-loader@"^8.0.0" from the root project
npm ERR!   2 more (copy-webpack-plugin, css-loader)
npm ERR! 
npm ERR! Could not resolve dependency:
npm ERR! dev mini-css-extract-plugin@"^0.9.0" from the root project
npm ERR! 
npm ERR! Conflicting peer dependency: [email protected]
npm ERR! node_modules/webpack
npm ERR!   peer webpack@"^4.4.0" from [email protected]
npm ERR!   node_modules/mini-css-extract-plugin
npm ERR! 
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force, or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.

二、原因

ERESOLVE与npm@7有关的问题很常见，因为npm7.x对某些事情比npm6.x更严格。通常，最简单的解决方法是将–legacy-peer-deps标志传递给npm(e.g.，npm i --legacy-peer-deps），或者使用npm@6。

如果这不能立即起作用，也许可以先删除node_modules和package-lock.json。它们将被重新创建。

三、解决方案

降级npm到6版本
或
使用npx指定npm的版本 npx -p npm@6 npm i --legacy-peer-deps