Turbopack Error: Panic in Project::project_path: Some("called Option::unwrap() on a None value")

[kingsword09]

Turbopack version: v15.3.0-canary.30-1-g48725b22c

Error message:

Panic in Project::project_path: Some("called `Option::unwrap()` on a `None` value")

Debug info:
- Execution of get_entrypoints_with_issues_operation failed
- Execution of EntrypointsOperation::new failed
- Execution of Project::entrypoints failed
- Execution of Project::app_project failed
- Panic in Project::project_path: Some("called `Option::unwrap()` on a `None` value")

[kingsword09]

After initializing a next.js project, everything works fine when I set outputFileTracingRoot to __dirname in next.config.ts, but an exception occurs when I set it to path.join(__dirname, "./"). The only difference between the two paths is that path.join(__dirname, "./") adds an extra / at the end.
reproduction code