运行npm run build打包时，报错如下：
image.png
我的package.json如下:
{
...
"devDependencies": {
"autoprefixer": "^7.1.2",
"babel-core": "^6.22.1",
"babel-eslint": "^8.2.1",
"babel-helper-vue-jsx-merge-props": "^2.0.3",
"babel-loader": "^7.1.1",
"babel-plugin-syntax-jsx": "^6.18.0",
"babel-plugin-transform-runtime": "^6.22.0",
"babel-plugin-transform-vue-jsx": "^3.5.0",
"babel-preset-env": "^1.3.2",
"babel-preset-stage-2": "^6.22.0",
"babel-register": "^6.22.0",
"chalk": "^2.0.1",
"chromedriver": "^2.27.2",
"copy-webpack-plugin": "^4.0.1",
"cross-spawn": "^5.0.1",
"css-loader": "^2.1.1",
"element-theme-chalk": "^2.8.2",
"element-ui": "^2.8.2",
"eslint": "^4.15.0",
"eslint-config-standard": "^10.2.1",
"eslint-friendly-formatter": "^3.0.0",
"eslint-loader": "^1.7.1",
"eslint-plugin-import": "^2.7.0",
"eslint-plugin-node": "^5.2.0",
"eslint-plugin-promise": "^3.4.0",
"eslint-plugin-standard": "^3.0.1",
"eslint-plugin-vue": "^4.0.0",
"extract-text-webpack-plugin": "^3.0.0",
"file-loader": "^1.1.11",
"friendly-errors-webpack-plugin": "^1.6.1",
"html-webpack-plugin": "^2.30.1",
"nightwatch": "^1.1.11",
"node-notifier": "^5.1.2",
"node-sass": "^4.12.0",
"optimize-css-assets-webpack-plugin": "^5.0.1",
"ora": "^1.2.0",
"portfinder": "^1.0.13",
"postcss-import": "^11.0.0",
"postcss-loader": "^2.0.8",
"postcss-url": "^7.2.1",
"rimraf": "^2.6.0",
"rxjs": "^6.5.2",
"rxjs-compat": "^6.5.2",
"sass-loader": "^7.1.0",
"selenium-server": "^3.0.1",
"semver": "^5.3.0",
"shelljs": "^0.7.6",
"style-loader": "^0.23.1",
"ts-loader": "^3.5.0",
"typescript": "^3.4.5",
"uglifyjs-webpack-plugin": "^1.1.1",
"url-loader": "^1.1.2",
"vue-class-component": "^7.1.0",
"vue-i18n": "^8.11.2",
"vue-i18n-extract": "^0.4.14",
"vue-loader": "^13.3.0",
"vue-property-decorator": "^8.1.1",
"vue-rx": "^6.2.0",
"vue-style-loader": "^3.0.1",
"vue-template-compiler": "^2.5.2",
"vuex": "^3.1.1",
"webpack": "^3.6.0",
"webpack-bundle-analyzer": "^3.3.2",
"webpack-dev-server": "^2.9.1",
"webpack-merge": "^4.1.0"
},
"engines": {
"node": ">= 6.0.0",
"npm": ">= 3.0.0"
},
"browserslist": [
"> 1%",
"last 2 versions",
"not ie <= 8"
]
}
后来查资料发现是版本问题,webpack是3.6.0的版本，但是optimize-css-assets-webpack-plugin是5.0.1的版本。后来把optimize-css-assets-webpack-plugin改为3.2.0的就可以了。
执行 npm i optimize-css-assets-webpack-plugin@3.2.0就可以改为3.2.0的版本了。
注：如果执行 npm i optimize-css-assets-webpack-plugin@3.2.0完成后出现如下提示，不要按提示执行，会把optimize-css-assets-webpack-plugin恢复到原来的版本，直接忽略提示就好了。
image.png
