Error when running gren init

When I run gren init, I get the following message:
```
$ gren init
You have to run this command in a git repo folder
```

However, this *is* a git repo folder, i.e. it has a .git subdirectory.

Unfortunately, there is no further information what might be wrong. Any suggestions?

首先，在包含 `.git` 目錄的 Git 儲存庫中重現 `gren init`，然後追蹤該命令使用的儲存庫偵測路徑。完成的標準是：命令能正確處理有效的儲存庫，或報告其無法繼續的實際原因；payload 未指定要執行的檔案或測試。

由索引模型根據 Issue 內容生成。