[BUG] Bash tool complete output capture failure on Windows (MINGW64 & CMD)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Issue Description:
The Bash tool executes commands successfully
but fails to capture any output whatsoever. All
commands return "Tool ran without output or
errors" regardless of the command type or
expected output.

Current Behavior:
All bash commands return "Tool ran without
output or errors" with no captured output,
regardless of command complexity.

Impact:

• Cannot see git command output (log, status,

diff)

• Cannot debug build/test command failures
• Cannot use bash tool for system diagnostics
• Severely limits development workflow

automation

What Should Happen?

Expected Behavior:
Commands should return their stdout/stderr
output to Claude Code for processing.

Error Messages/Logs

Steps to Reproduce

Steps to Reproduce:

1. Open Claude Code in Windows environment
2. Execute any bash command that should produce

output

1. Observe that execution succeeds but no

output is captured

Environment:

• OS: Windows 10 (MINGW64_NT-10.0-26100

3.6.4-b9f03e96.x86_64)

• Claude Code version: [Current version]
• Tested terminals: Git Bash (MINGW64), Windows

Command Prompt

• Working directory: Valid git repository

Test Cases Attempted:
# Basic commands
echo "test"
pwd
ls
whoami

# Git commands
git log -1
git status
git --version

# Output redirection
echo "test" 2>&1
printf "test\n"
echo "test" > temp.txt && cat temp.txt && rm
temp.txt

# Windows-specific
cmd.exe /c "echo test"
powershell.exe -Command "Write-Output 'test'"

Configuration Verified:

• .claude/permissions.json contains:

{"permissions": {"allow": ["Bash(*)"], "deny":
[], "ask": []}}

• Commands execute successfully in native

terminals (Git Bash, CMD, PowerShell)

• Other Claude Code tools (Read, Edit, Write,

Glob, Grep) function normally

Environment Testing:

• Issue reproduces in both Git Bash (MINGW64)

and Windows Command Prompt

• Same commands work perfectly when executed

directly in terminal

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

1.0.113

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Cursor

Additional Information

This appears to be a Windows-specific issue
with the Bash tool's output stream capture
mechanism. Command execution succeeds (no
errors), but stdout/stderr capture fails
completely across all command types and shell
environments.