#npm i 错误解决记录#

最开始错误 ：拉取代码，增加依赖时，报错

问题：

在安装sass-loader@10.1.1时，发现与现有的webpack版本有冲突。

当前项目已经安装了webpack@4.28.4（通过peer dependency requirements from other packages），但是sass-loader@10.1.1要求webpack的版本是^4.36.0 || ^5.0.0。

而当前项目中的webpack版本是4.28.4，低于4.36.0，因此不满足要求。

（sass-loader@10.1.1 与项目中已安装的 webpack@4.28.4 版本不兼容）

npm error code ERESOLVE
npm error ERESOLVE could not resolve
npm error
npm error While resolving: sass-loader@10.1.1
npm error Found: webpack@4.28.4
npm error node_modules/webpack
npm error   peer webpack@"^4.0.0" from @intervolga/optimize-cssnano-plugin@1.0.6
npm error   node_modules/@intervolga/optimize-cssnano-plugin
npm error     @intervolga/optimize-cssnano-plugin@"^1.0.5" from @vue/cli-service@3.5.3
npm error     node_modules/@vue/cli-service
npm error       dev @vue/cli-service@"3.5.3" from the root project
npm error   peer webpack@"^4.0.0 || ^5.0.0" from @soda/friendly-errors-webpack-plugin@1.8.0
npm error   node_modules/@soda/friendly-errors-webpack-plugin
npm error     @soda/friendly-errors-webpack-plugin@"^1.7.1" from @vue/cli-service@3.5.3
npm error     node_modules/@vue/cli-service
npm error       dev @vue/cli-service@"3.5.3" from the root project
npm error   19 more (@vue/cli-plugin-babel, @vue/cli-plugin-eslint, ...)
npm error
npm error Could not resolve dependency:
npm error peer webpack@"^4.36.0 || ^5.0.0" from sass-loader@10.1.1
npm error node_modules/sass-loader
npm error   dev sass-loader@"10.1.1" from the root project
npm error
npm error Conflicting peer dependency: webpack@5.99.9
npm error node_modules/webpack
npm error   peer webpack@"^4.36.0 || ^5.0.0" from sass-loader@10.1.1
npm error   node_modules/sass-loader
npm error     dev sass-loader@"10.1.1" from the root project
npm error
npm error Fix the upstream dependency conflict, or retry
npm error this command with --force or --legacy-peer-deps
npm error to accept an incorrect (and potentially broken) dependency resolution.

尝试解决：npm uninstall sass-loader

但此时npm install sass-loader@8 --save-dev 执行时还是有问题（原因sass-loader@8.0.2也需要webpack@^4.36.0 || ^5.0.0，而我们的webpack是4.28.4（低于4.36.0），所以仍然不满足）

pm error code ERESOLVE
npm error ERESOLVE could not resolve
npm error
npm error While resolving: jnpf-web@3.4.1
npm error Found: webpack@4.28.4
npm error node_modules/webpack
npm error   peer webpack@"^4.0.0" from @intervolga/optimize-cssnano-plugin@1.0.6
npm error   node_modules/@intervolga/optimize-cssnano-plugin
npm error     @intervolga/optimize-cssnano-plugin@"^1.0.5" from @vue/cli-service@3.5.3
npm error     node_modules/@vue/cli-service
npm error       dev @vue/cli-service@"3.5.3" from the root project
npm error   peer webpack@"^4.0.0 || ^5.0.0" from @soda/friendly-errors-webpack-plugin@1.8.0
npm error   node_modules/@soda/friendly-errors-webpack-plugin
npm error     @soda/friendly-errors-webpack-plugin@"^1.7.1" from @vue/cli-service@3.5.3
npm error     node_modules/@vue/cli-service
npm error       dev @vue/cli-service@"3.5.3" from the root project
npm error   19 more (@vue/cli-plugin-babel, @vue/cli-plugin-eslint, ...)
npm error
npm error Could not resolve dependency:
npm error dev sass-loader@"8" from the root project
npm error
npm error Conflicting peer dependency: webpack@5.99.9
npm error node_modules/webpack
npm error   peer webpack@"^4.36.0 || ^5.0.0" from sass-loader@8.0.2
npm error   node_modules/sass-loader
npm error     dev sass-loader@"8" from the root project
npm error
npm error Fix the upstream dependency conflict, or retry
npm error this command with --force or --legacy-peer-deps
npm error to accept an incorrect (and potentially broken) dependency resolution.

 

  解决：

先 npm uninstall sass-loader

再npm install sass-loader@7.3.1 --save-dev

（

查阅sass-loader的版本历史：

- sass-loader v7.x 支持 webpack 4 (包括早期版本)

- 根据错误信息，sass-loader@8.0.2需要webpack>=4.36.0，所以如果我们用7.x版本，可能就可以兼容webpack4.28.4。

）

注意： 

不要使用 --force 或 --legacy-peer-deps：这会导致依赖树混乱，可能在运行时崩溃