[BUG]

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?

Every Bash tool invocation returns Exit code 1 with zero output (no stdout, no stderr), regardless of the command or
shell configuration. This includes trivial commands like echo hello, git --version, and even true (a no-op that
produces no output).

This appears related to the reported issue where stdout-producing commands fail with exit code 1 on Windows but true
succeeds. However, in my case even true fails, suggesting the underlying problem may be broader or have multiple root
causes.

What Should Happen?

Commands should execute and return their output normally.

Error Messages/Logs

No error messages — just Exit code 1 with empty output on every command. No log directories exist
  (%USERPROFILE%\.claude\logs and %APPDATA%\claude-code are both missing).

Steps to Reproduce

1. Open Claude Code on Windows 11
2. Run any Bash tool command (e.g. echo hello, git --version, true)
3. All return Exit code 1 with no output

Tested with all shell configurations — all fail identically:

  ┌───────────────┬───────────────────────────────────────────────────────────┬─────────────┐
  │     Shell     │                   preferredShell value                    │   Result    │
  ├───────────────┼───────────────────────────────────────────────────────────┼─────────────┤
  │ Git Bash      │ C:\Program Files\Git\bin\bash.exe                         │ Exit code 1 │
  ├───────────────┼───────────────────────────────────────────────────────────┼─────────────┤
  │ PowerShell    │ C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe │ Exit code 1 │
  ├───────────────┼───────────────────────────────────────────────────────────┼─────────────┤
  │ cmd.exe       │ C:\Windows\System32\cmd.exe                               │ Exit code 1 │
  ├───────────────┼───────────────────────────────────────────────────────────┼─────────────┤
  │ WSL           │ C:\Windows\System32\wsl.exe                               │ Exit code 1 │
  ├───────────────┼───────────────────────────────────────────────────────────┼─────────────┤
  │ No preference │ (removed preferredShell entirely)                         │ Exit code 1 │
  └───────────────┴───────────────────────────────────────────────────────────┴─────────────┘

Claude Code was restarted after each change.

Key evidence: Node.js child_process works fine from the same terminal:
node -e "console.log(require('child_process').execSync('echo hello').toString())"
Prints hello successfully. WSL also works when invoked directly (wsl echo hello).

Ruled out: cmd.exe AutoRun registry keys (not set), antivirus (nothing blocked), reinstalling Git and Claude Code,
running as Administrator.

Claude model: Opus

Is this a regression? Unknown — Bash tool has never worked for me.

Claude Code version: 2.1.74

API platform: Anthropic API

OS: Windows 11 Enterprise 10.0.26200

Terminal/Shell: Tested Git Bash, PowerShell, cmd.exe, WSL — all fail

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

Claude Code version: 2.1.74

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_