[BUG] Shell not found on Windows even with SHELL env variable set

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?

OS: Windows 10
SHELL variable is set to C:\Program Files\Git\bin\bash.exe
Still getting error: "No suitable shell found. Claude CLI requires a Posix shell environment"

What Should Happen?

Claude Code should be able to execute shell commands when SHELL environment variable is correctly set to Git bash on Windows.

Error Messages/Logs

No suitable shell found. Claude CLI requires a Posix shell environment. Please ensure you have a valid shell installed and the SHELL environment variable set.

Steps to Reproduce

1. Windows 10, VS Code with Claude Code extension
2. Set user environment variable: SHELL = C:\Program Files\Git\bin\bash.exe
3. Restart computer
4. Open VS Code and use Claude Code
5. Claude tries to run any shell command → error occurs despite SHELL being correctly set

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.84 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

Using Claude Code VS Code extension on Windows 10.
SHELL environment variable is set to: C:\Program Files\Git\bin\bash.exe
Git Bash is installed and working. Restarted computer but the issue persists.