问小程序 生产环境 部署代码失败？

错误提示如下（在部署之前已经点击了“安装依赖”并提示安装成功）：

代码部署失败

module.js:487 throw err; ^ Error: Cannot find module 'koa-static' at Function.Module._resolveFilename (module.js:485:15) at Function.Module._load (module.js:437:25) at Module.require (module.js:513:17) at require (internal/module.js:11:18) at Object.<anonymous> (/data/release/node-weapp-demo/app.js:8:19) at Module._compile (module.js:569:30) at Object.Module._extensions..js (module.js:580:10) at Module.load (module.js:503:32) at tryModuleLoad (module.js:466:12) at Function.Module._load (module.js:458:3)