WSL+VSCode: bun index.html server inaccessible via port forwarding (discussion before filing issue)

[TNTSuperMan]

Since the reproducibility is not sufficient to file an Issue, I would like to start a discussion here.

When running bun index.html inside WSL2 via VSCode Remote, the server starts and VSCode automatically sets up port forwarding. However, accessing it from the host (Windows 10) results in an ERR_CONNECTION_RESET error.
But when I ran a command like curl http://localhost:3000 on the WSL machine, it returned a successful response.

In contrast, when running a script server such as bun index.ts (using Bun.serve), the server works fine and can be accessed normally.

My assumption is that this might be a bug in Bun, but due to the complexity of port forwarding and environment differences, reproducibility may be difficult. Therefore, I would like to discuss the details here before filing an Issue.

Environment

• Windows 10 (latest, ESU program registered)
• WSL2 (Ubuntu 24.04.3)
• Visual Studio Code (latest)
• Microsoft Edge (latest)