fix(tools): suppress Windows AutoRun stderr in shell commands

[mvanhorn]

Summary

On Windows, every execute_shell_command call produces spurious "The system cannot find the path specified." stderr output, even when the command succeeds with returncode 0. This happens because subprocess.Popen(shell=True) invokes cmd.exe, which runs AutoRun scripts from the registry (HKCU\Software\Microsoft\Command Processor\AutoRun). If AutoRun references a nonexistent path, stderr gets polluted.

Changes

• shell.py: Replace shell=True with an explicit ["cmd", "/D", "/S", "/C", cmd] invocation. The /D flag disables AutoRun processing (Microsoft docs). The /S flag ensures the inner command string is passed through unchanged, preserving pipes, redirects, and shell builtins.

This function is only called on Windows (sys.platform == "win32" gate at line 166), so non-Windows platforms are unaffected.

Testing

The fix follows standard Windows practice for subprocess invocation. The existing creationflags=subprocess.CREATE_NEW_PROCESS_GROUP handling is preserved. Commands with pipes (echo a | sort), redirects (echo a > file), and shell builtins (dir, type) continue to work because cmd /S /C processes them.

Fixes #1545

This contribution was developed with AI assistance (Claude Code).

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses an issue on Windows where execute_shell_command calls would produce unnecessary stderr output due to cmd.exe attempting to run nonexistent AutoRun scripts. The solution involves explicitly invoking cmd.exe with flags to disable AutoRun and correctly parse the command, thereby cleaning up the stderr output without affecting functionality or non-Windows platforms.

Highlights

• Windows stderr suppression: Modified execute_shell_command to prevent spurious "The system cannot find the path specified." stderr output on Windows by disabling cmd.exe AutoRun scripts.
• Subprocess invocation on Windows: Replaced shell=True with an explicit ["cmd", "/D", "/S", "/C", cmd] invocation for Windows, ensuring AutoRun is disabled (/D) and command parsing is preserved (/S).

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Changelog

• src/copaw/agents/tools/shell.py
  • Modified _execute_subprocess_sync to explicitly construct the command array for subprocess.Popen on Windows.
  • Switched shell=True to shell=False and passed the wrapped command list.
  • Added comments explaining the purpose of the /D and /S flags for cmd.exe.

Activity

• Fixed issue [Bug]:Windows 平台 execute_shell_command 工具 stderr 显示"系统找不到指定的路径。"错误 #1545, which reported spurious stderr output on Windows.
• The contribution was developed with AI assistance (Claude Code).

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[gemini-code-assist]

Code Review

This pull request effectively resolves an issue with spurious stderr output on Windows during shell command execution by disabling AutoRun scripts. The approach of explicitly calling cmd.exe with the /D flag is a clean and targeted fix. The change is correctly scoped to Windows environments. I have one suggestion to improve the accuracy of a code comment for better long-term maintainability.

[xieyxclack]

LGTM

[github-actions]

Welcome to CoPaw! 🎉

Thank you @mvanhorn for your first contribution! Your PR has been merged. 🚀

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[mvanhorn]

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