``` > cross-env PORT=9000 node webpack/watch.js 'cross-env' 不是内部或外部命令，也不是可运行的程序 或批处理文件。 npm ERR! code ELIFECYCLE npm ERR! errno 1 npm ERR! youzan@1.0.7 dev: `cross-env PORT=9000 node webpack/watch.js` npm ERR! Exit status 1 npm ERR! npm ERR! Failed at the youzan@1.0.7 dev script. npm ERR! This is probably not a problem with npm. There is likely additional logging output above. npm WARN Local package.json exists, but node_modules missing, did you mean to install? npm ERR! A complete log of this run can be found in: ``` ``` npm install ```