Javascript build.com在netlify上失败。Can'；t部署网站

github项目：

没什么好说的，我试图部署这个站点，但我总是出错。不知道是纱线、我的代码还是其他问题

错误日志：

7:14:28 PM: $ yarn run build
7:14:28 PM: bash: yarn: command not found
7:14:28 PM: ​
7:14:28 PM: ┌─────────────────────────────┐
7:14:28 PM: │   "build.command" failed    │
7:14:28 PM: └─────────────────────────────┘
7:14:28 PM: ​
7:14:28 PM:   Error message
7:14:28 PM:   Command failed with exit code 127: yarn run build
7:14:28 PM: ​
7:14:28 PM:   Error location
7:14:28 PM:   In Build command from Netlify app:
7:14:28 PM:   yarn run build
7:14:28 PM: ​
7:14:28 PM:   Resolved config
7:14:28 PM:   build:
7:14:28 PM:     command: yarn run build
7:14:28 PM:     commandOrigin: ui
7:14:28 PM:     publish: /opt/build/repo/build
7:14:28 PM: Caching artifacts
7:14:28 PM: Started saving node modules
7:14:28 PM: Finished saving node modules
7:14:28 PM: Started saving build plugins
7:14:28 PM: Finished saving build plugins
7:14:28 PM: Started saving pip cache
7:14:28 PM: Finished saving pip cache
7:14:28 PM: Started saving emacs cask dependencies
7:14:28 PM: Finished saving emacs cask dependencies
7:14:28 PM: Started saving maven dependencies
7:14:28 PM: Finished saving maven dependencies
7:14:28 PM: Started saving boot dependencies
7:14:28 PM: Finished saving boot dependencies
7:14:28 PM: Started saving go dependencies
7:14:28 PM: Finished saving go dependencies
7:14:31 PM: Error running command: Build script returned non-zero exit code: 1
7:14:31 PM: Failing build: Failed to build site
7:14:31 PM: Failed during stage 'building site': Build script returned non-zero exit code: 1
7:14:31 PM: Finished processing build request in 1m0.62316905s