解决了:
问题出在package babel-loader
,最新版本需要@ babel / core。将版本降级到7.x,现在可以了
"devDependencies": {
"babel-core": "^6.26.3",
"babel-loader": "^7.1.5",
"babel-preset-env": "^1.7.0",
"babel-preset-react": "^6.24.1",
"html-webpack-plugin": "^3.2.0",
"webpack": "^4.17.1",
"webpack-cli": "^3.1.0",
"webpack-dev-server": "^3.1.6"
},
"dependencies": {
"react": "^16.4.2",
"react-dom": "^16.4.2"
}