[BUG] cygpath: command not found error when running Claude Code in PowerShell/Windows Terminal

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

Claude Code fails to execute in PowerShell and Windows Terminal on Windows due to attempting to use the cygpath command, which is only available in Git Bash/MINGW/Cygwin environments. The tool works
correctly in Git Bash but crashes in native Windows shells.

Environment

• OS: Windows 10/11 (MINGW64_NT-10.0-26100)
• OS Version: MINGW64_NT-10.0-26100 3.6.3-7674c51e.x86_64
• Platform: win32
• Claude Code Version: [check with claude --version if available]
• Claude Code Executable Path: B:/~BUN/root/claude.exe
• Node.js Version: [if known]

Shells Tested

• ✓ Git Bash (MINGW64): Works correctly
• ✗ PowerShell: Fails with error
• ✗ Windows Terminal: Fails with error

Working Directory

C:\Projects_POC\adw_mcp\adw_mcp (Git repository)

Steps to Reproduce

1. Open PowerShell or Windows Terminal (not Git Bash)
2. Navigate to any directory (tested with a Git repository)
3. Run claude command to start Claude Code
4. Observe the error

What Should Happen?

Expected Behavior

Claude Code should work in all Windows shell environments (PowerShell, CMD, Windows Terminal, Git Bash) without requiring Cygwin-specific utilities.

Actual Behavior

Claude Code crashes with the following error:

Sublimating… (esc to interrupt)

• /usr/bin/bash: line 1: cygpath: command not found

-

• genericNodeError (node:child_process:1010:22)
• checkExecSyncError (node:child_process:470:27)
• execSync (node:child_process:278:31)
• wY (B:/~BUN/root/claude.exe:54:3338)
• Gb (B:/~BUN/root/claude.exe:70:418)
• tpI (B:/~BUN/root/claude.exe:4530:25154)
• pk (B:/~BUN/root/claude.exe:4530:28328)
• <anonymous> (B:/~BUN/root/claude.exe:4530:28096)
• some (native:1:11)
• <anonymous> (B:/~BUN/root/claude.exe:4530:28088)

This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason:
Error: Command failed: cygpath -u 'c:\projects_poc\adw_mcp\adw_mcp'
/usr/bin/bash: line 1: cygpath: command not found

at genericNodeError (node:child_process:1010:22)
at checkExecSyncError (node:child_process:470:27)
at execSync (node:child_process:278:31)
at wY (B:/~BUN/root/claude.exe:54:3338)
at Gb (B:/~BUN/root/claude.exe:70:418)
at tpI (B:/~BUN/root/claude.exe:4530:25154)
at pk (B:/~BUN/root/claude.exe:4530:28328)
at <anonymous> (B:/~BUN/root/claude.exe:4530:28096)
at some (native:1:11)
at <anonymous> (B:/~BUN/root/claude.exe:4530:28088)

Root Cause Analysis

The error indicates Claude Code is attempting to execute:
cygpath -u 'c:\projects_poc\adw_mcp\adw_mcp'

The cygpath utility is only available in Cygwin/MINGW/Git Bash environments and is used to convert Windows paths to Unix-style paths. When running in native Windows shells (PowerShell, CMD, Windows
Terminal), this command is not available, causing the crash.

Expected Fix

Claude Code should:

1. Detect the current shell environment
2. Only use cygpath when running in Cygwin/MINGW/Git Bash
3. Use native Windows path handling in PowerShell/CMD/Windows Terminal
4. Or use Node.js built-in path utilities (path.resolve(), path.normalize()) that work cross-platform

Current Workaround

Use Git Bash instead of PowerShell or Windows Terminal when running Claude Code on Windows.

Additional Context

• Git is installed and available in PATH
• The repository is a valid Git repository
• All operations work correctly when using Git Bash
• The issue appears to be related to shell environment detection/path conversion logic

Error Messages/Logs

This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason:
Error: Command failed: cygpath -u 'c:\projects_poc\adw_mcp\adw_mcp'
/usr/bin/bash: line 1: cygpath: command not found

    at genericNodeError (node:child_process:1010:22)
    at checkExecSyncError (node:child_process:470:27)
    at execSync (node:child_process:278:31)
    at wY (B:/~BUN/root/claude.exe:54:3338)
    at Gb (B:/~BUN/root/claude.exe:70:418)
    at tpI (B:/~BUN/root/claude.exe:4530:25154)
    at pk (B:/~BUN/root/claude.exe:4530:28328)
    at <anonymous> (B:/~BUN/root/claude.exe:4530:28096)
    at some (native:1:11)
    at <anonymous> (B:/~BUN/root/claude.exe:4530:28088)

Steps to Reproduce

Steps to Reproduce

1. Open PowerShell or Windows Terminal (not Git Bash)
2. Navigate to any directory (tested with a Git repository)
3. Run claude command to start Claude Code
4. Observe the error

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.15

Claude Code Version

2.1.15

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

The version is the same thing, the error started occurring when I switched from the npm installation to the claude native installation. I got a popup stating I should switch to the native installation following the new version release. Once I ran claude install and switched to the native installation, I started getting errors like the following:

<img width="1809" height="680" alt="Image" src="https://github.com/user-attachments/assets/8dbad0fd-8beb-4781-9c71-369cf265ffe5" />

<img width="898" height="332" alt="Image" src="https://github.com/user-attachments/assets/8643331b-e930-4d5b-abed-d334ed374e0f" />