[BUG] Windows - Bash tool fails with "Permission denied" on Windows when username contains a space

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?

Description

On Windows (Git Bash / MSYS2 / PowerShell), every Bash tool invocation produces a spurious error when the Windows user profile path contains a space:

/usr/bin/bash: line 1: /c/Users/John: Permission denied

The shell interprets the first word of the unquoted $HOME path (/c/Users/John) as a command to execute, because HOME is set to /c/Users/John Doe and is expanded without quotes somewhere in Claude Code's internal shell initialization.

Environment

• OS: Windows 11 Pro (25H2) x86\_64, build 10.0.26200
• Shell: Git Bash (MSYS2) via /usr/bin/bash, PowerShell
• Terminal: Warp / Windows Terminal
• Claude Code version: 2.1.45/47/48/50 (tested across multiple versions)
• HOME: /c/Users/John Doe

What Should Happen?

Expected behavior

• $HOME should be quoted wherever it is used in Claude Code's bash initialization (e.g. "$HOME")
• Commands on accounts with spaces in the username should execute without spurious errors
• Exit codes should reflect actual command success/failure

Error Messages/Logs

Error: Exit code 1
     /usr/bin/bash: line 1: /c/Users/John: Permission denied

     /usr/bin/bash: line 1: /c/Users/John: Permission denied

Steps to Reproduce

Steps to reproduce

1. Have a Windows user account with a space in the name (e.g. John Doe)
2. Run any Bash command in Claude Code, even a trivial one:

``bash
echo "hello"
``

1. Observe the error appended to every command output:

``
/usr/bin/bash: line 1: /c/Users/John: Permission denied
``

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.44

Claude Code Version

2.1.50

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

Key observations

• The error appears on every single Bash invocation, including bash --norc --noprofile -c "echo clean", confirming the issue is in Claude Code's own shell wrapper, not in user profile files (.bashrc, .bash_profile, etc.).
• Commands still execute and produce correct output — the error is additional.
• The error is always line 1, suggesting it occurs during Claude Code's shell environment initialization before the user's command runs.
• All exit codes are reported as 1 regardless of actual command success, which can break scripts that check exit codes.

Expected behavior

• $HOME should be quoted wherever it is used in Claude Code's bash initialization (e.g. "$HOME")
• Commands on accounts with spaces in the username should execute without spurious errors
• Exit codes should reflect actual command success/failure

Workarounds attempted

| Workaround | Result |
| ---------------------------------------------- | -------------------------------------------------------------------------------------- |
| bash --norc --noprofile | Error persists — not a profile issue |
| Set CLAUDE_CONFIG_DIR to space-free junction | Fixes config paths but not the shell init error |
| Set HOME to 8.3 short name in .bashrc | HOME is correct after profile loads, but error still fires before profile is sourced |

Root cause hypothesis

Claude Code's Bash tool likely constructs the shell environment or evaluates $HOME without double-quoting it before the user's command is executed. On Windows/MSYS2 where HOME can contain spaces, the unquoted expansion causes word splitting. The first token (/c/Users/John) is treated as a command, producing Permission denied.