bash tool: external_directory prompt skipped when realpath is missing

[MaxMiksa]

Description

The bash tool tries to detect when a command targets paths outside the project directory to request external_directory permission. Current path resolution relies on an external realpath binary, which is not reliably available on Windows / some environments, so the external directory prompt can be skipped.

Plugins

N/A

OpenCode version

dev (local checkout @ 213c0e18a, package packages/opencode v1.1.36)

Steps to reproduce

1. Run in an environment where realpath is not present on PATH (common on Windows)
2. Execute a bash tool command that leaves the project directory (e.g. cd ..)
3. Observe whether an external_directory permission request is issued

Operating System

Windows 11

Terminal

Windows Terminal

Expected

Even without realpath, Opencode should still resolve candidate target paths (e.g. via path.resolve) and request external_directory permission when leaving Instance.directory.

Actual

Path resolution fails silently when realpath is missing, resulting in no external_directory permission request for commands like cd .. / file operations targeting outside directories.

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Windows: Git Bash auto-detection derives invalid bash.exe path #10871: Windows: Git Bash auto-detection derives invalid bash.exe path

Both issues involve bash tool path resolution issues on Windows and missing external dependencies/binaries. While #10871 focuses on Git Bash auto-detection, #10872 addresses a related path resolution problem when realpath is unavailable. They may share root causes around Windows path handling in the bash tool.

Feel free to ignore if your specific case differs.

[MaxMiksa]

Thanks! Related to Windows bash/tooling, but this one is distinct: bash tool external-directory detection currently relies on an external realpath binary. In environments where realpath isn’t available (common on Windows), the external_directory prompt can be skipped.

PR #10874 removes the external dependency by using internal path.resolve + fs.realpath fallback and adds a regression test.