[ Bash shell crashes on every invocation on Windows — MSYS2 fatal error (exit code 3221225477)]

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 call from Claude Code crashes immediately with a fatal MSYS2 error. The shell never executes any command — it fails on startup. All file tools (Read, Write, Edit, Grep, Glob) work fine, but nothing requiring shell execution works.

Error output:
Exit code 3221225477
1 [main] bash (10644) C:\Program Files\Git\bin\..\usr\bin\bash.exe: *** fatal error - add_item ("\??\C:\Program
Files\Git", "/", ...) failed, errno 1

What Should Happen?

The Bash shell should execute commands successfully, OR the CLAUDE_CODE_SHELL environment variable should be respected
so users can configure PowerShell as a fallback shell on Windows.

Error Messages/Logs

Steps to Reproduce

Steps to Reproduce (clear and replace):

1. Install Claude Code on Windows 11 with Git Bash as the shell
2. Start a Claude Code session
3. Ask Claude to run any shell command (e.g., "run glab --version")
4. Observe the Bash tool call crash immediately with exit code 3221225477

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.63

Claude Code Version

2.1.63

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_