当尝试简单地使用cp -r project clone_project复制整个VueJS项目时，从clone_project目录运行npm run serve时出现以下错误：
> design@0.1.0 serve /Users/path_to_clone_project/clone_project
> vue-cli-service serve
internal/modules/cjs/loader.js:613
throw err;
^
Error: Cannot find module '../package.json'
Require stack:
- /Users/path_to_clone_project/clone_project/node_modules/.bin/vue-cli-service
at Function.Module._resolveFilename (internal/modules/cjs/loader.js:610:15)
at Function.Module._load (internal/modules/cjs/loader.js:526:27)
at Module.require (internal/modules/cjs/loader.js:666:19)
at require (internal/modules/cjs/helpers.js:16:16)
at Object.<anonymous> (/Users/path_to_clone_project/clone_project/node_modules/.bin/vue-cli-service:5:25)
at Module._compile (internal/modules/cjs/loader.js:759:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:770:10)
at Module.load (internal/modules/cjs/loader.js:628:32)
at Function.Module._load (internal/modules/cjs/loader.js:555:12)
at Function.Module.runMain (internal/modules/cjs/loader.js:824:10)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! design@0.1.0 serve: `vue-cli-service serve`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the design@0.1.0 serve script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
原始项目是使用 Vue CLI 工具创建的。我不明白这个错误，因为package.json文件是按预期与项目的其余部分一起复制的。
删除node_modules文件夹并运行npm install。
npm install将创建node_modules文件夹并安装 package.json 中定义的所有包。
然后运行npm run serve