如果你使用了element-ui的el-tabs组件，并且想要单独升级element-ui至2.10.0，你会发现，使用了el-tabs组件的页面只要打开就卡死。原因是element-ui~2.10.0采用了不兼容vue~2.5.10的写法。于是我尝试系统性升级vue全家桶，这也是为系统赋予更多能力做准备。结果遇到一些报错，这里记录一下。
升级过程 当前版本vue: 2.5.10
vue-loader: 13.5.0
vue-router: 3.0.1
vuex: 3.0.1
axios: 0.17.1
element-ui: 2.2.2
目标版本vue: 2.6.10
vue-loader: 15.7.0
vue-router: 3.0.3
vuex: 3.1.1
axios: 0.18.1
element-ui: 2.10.0
报错1(包版本不匹配)修改package.json中的依赖包版本号之后，npm install一波后就报错了。
Vue packages version mismatch: - vue@2.6.10 - vue-template-compiler@2.5.10 This may cause things to work incorrectly. Make sure to use the same version for both. If you are using vue-loader@>=10.0, simply update vue-template-compiler. If you are using vue-loader@<10.0 or vueify, re-installing vue-loader/vueify should bump vue-template-compiler to the latest. @ ./src/router/modules/test/index.js 22:23-67 @ ./src/router/common.js @ ./src/router/index.js @ ./src/main.js @ multi (webpack)-dev-server/client?:9532 webpack/hot/dev-server babel-polyfill ./src/main.js分析：vue和vue-template-compiler两个包的版本不匹配，需要升级vue-template-compile。github搜索这个包搜不到，最后在npm包官网找到了。
解决方案：升级vue-template-compile: 2.6.10
报错2(vue-loader) | | <section> | <el-form :model="dataForm" :rules="rules" ref="dataForm" label-width="125px"> | <el-form-item label="法定节假日名称" prop="name"> @ ./src/views/backend/enterprise/holiday/add-public-holiday.vue 1:0-97 30:4-35:6 30:81-35:5 @ ./src/views lazy ^\.\/.*$ @ ./src/authority/generate-routes.js @ ./src/store/modules/user.js @ ./src/store/index.js @ ./src/main.js @ multi (webpack)-dev-server/client?:9532 webpack/hot/dev-server babel-polyfill ./src/main.js error in ./src/views/backend/enterprise/holiday/add-special-holiday.vue?vue&type=template&id=09f84cb0& Module parse failed: Unexpected token (2:0) You may need an appropriate loader to handle this file type.分析：经观察，发现可能是不识别vue文件或其中某部分，于是从vue-loader入手，也在网上查阅了一些资料，需要在webpack的plugins中加入vue-loader/lib/plugin。
解决方案：
const VueLoaderPlugin = require('vue-loader/lib/plugin') plugins: [ new VueLoaderPlugin(), // 其他插件 ... ] 报错3(postcss-loader) (Emitted value instead of an instance of Error) ⚠️ PostCSS Loader Previous source map found, but options.sourceMap isn't set. In this case the loader will discard the source map entirely for performance reasons. See https://github.com/postcss/postcss-loader#sourcemap for more information. @ ./node_modules/vue-style-loader!./node_modules/css-loader?{"sourceMap":false}!./node_modules/vue-loader/lib/loaders/stylePostLoader.js!./node_modules/postcss-loader/lib?{"sourceMap":false}!./node_modules/vue-loader/lib?{"loaders":{"css":["vue-style-loader",{"loader":"css-loader","options":{"sourceMap":false}}],"postcss":["vue-style-loader",{"loader":"css-loader","options":{"sourceMap":false}}],"less":["vue-style-loader",{"loader":"css-loader","options":{"sourceMap":false}},{"loader":"less-loader","options":{"sourceMap":false}}],"sass":["vue-style-loader",{"loader":"css-loader","options":{"sourceMap":false}},{"loader":"sass-loader","options":{"indentedSyntax":true,"sourceMap":false}}],"scss":["vue-style-loader",{"loader":"css-loader","options":{"sourceMap":false}},{"loader":"sass-loader","options":{"sourceMap":false}}],"stylus":["vue-style-loader",{"loader":"css-loader","options":{"sourceMap":false}},{"loader":"stylus-loader","options":{"sourceMap":false}}],"styl":["vue-style-loader",{"loader":"css-loader","options":{"sourceMap":false}},{"loader":"stylus-loader","options":{"sourceMap":false}}]},"cssSourceMap":false,"cacheBusting":true,"transformToRequire":{"video":["src","poster"],"source":"src","img":"src","image":"xlink:href"}}!./src/views/iot-supervise/truck/truck-carousel.vue?vue&type=style&index=0&lang=css& 4:14-1577 14:3-18:5 15:22-1585 @ ./src/views/iot-supervise/truck/truck-carousel.vue?vue&type=style&index=0&lang=css& @ ./src/views/iot-supervise/truck/truck-carousel.vue @ ./src/views lazy ^\.\/.*$ @ ./src/authority/generate-routes.js @ ./src/store/modules/user.js @ ./src/store/index.js @ ./src/main.js @ multi (webpack)-dev-server/client?:9532 webpack/hot/dev-server babel-polyfill ./src/main.js分析：这里面的错误是关于postcss-loader的，只要将config/index.js中dev.cssSourceMap设置为true即可。
警告1(svg-sprite-loader)升级过程中还遇到了一个警告，虽然不影响功能，但是看着还是很难受的。
in ./src/icons/svg/workList.svg svg-sprite-loader exception. 28 rules applies to D:\coollu\projects\coollu-v3\source-code\v1.0.1\update-elementui-test\src\icons\svg\workList.svg @ ./src/icons/svg \.svg$ @ ./src/icons/index.js @ ./src/main.js @ multi (webpack)-dev-server/client?:9532 webpack/hot/dev-server babel-polyfill ./src/main.js搜索关键词后，发现网上并没有此类答案。因此我考虑是版本问题，于是升级svg-sprite-loader至最新版本4.1.6，解决了这个警告问题。
总结至此升级过程就完成了！顺便一提，系统性升级必须要经过全面测试，否则你难以保证完全向下兼容哦！