Failed to deploy

It seems this was working a few weeks ago, but something change on DO's side.

When I try to deploy this repo using the CLI I get build errors.

`./build.sh: line 5: virtualenv: command not found`

There is no documentation on the build.sh files so I have no idea what could go wrong .

先阅读 build.sh，尤其是第 5 行，并复现 CLI 部署，以确认 virtualenv 命令失败。跟踪仓库的 Python 环境在部署期间是如何创建的；当示例部署时不再出现报告的构建错误，即表示完成。

由索引模型根据 Issue 内容生成。