[BUG] Claude Code fails to launch on Windows: MSYS2 cygpath fork failure (0xC0000142)

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?

ERROR Command failed: cygpath -u 'c:\users\colli\documents\vs'

node:child_process:1010:22

• genericNodeError (node:child_process:1010:22)
• checkExecSyncError (node:child_process:470:27)
• execSync (node:child_process:278:31)
• oR (B:/~BUN/root/claude.exe:29:3503)
• <anonymous> (B:/~BUN/root/claude.exe:63:1174)
• D (B:/~BUN/root/claude.exe:62:19481)
• uHf (B:/~BUN/root/claude.exe:6165:4940)
• wm (B:/~BUN/root/claude.exe:6165:8149)
• <anonymous> (B:/~BUN/root/claude.exe:6165:7917)
• some (native:1:11)

1010827 [main] bash 728 dofork: child -1 - forked process 7484 died unexpectedly, retry 0, exit code 0xC0000142, errno 11
3021343 [main] bash 728 dofork: child -1 - forked process 11884 died unexpectedly, retry 0, exit code 0xC0000142, errno 11
7032961 [main] bash 728 dofork: child -1 - forked process 4108 died unexpectedly, retry 0, exit code 0xC0000142, errno 11

What Should Happen?

Claude Code should launch successfully and resolve the working directory path without the cygpath subprocess crashing.

Error Messages/Logs

ERROR  Command failed: cygpath -u 'c:\users\colli\documents\vs'

 node:child_process:1010:22

 - genericNodeError (node:child_process:1010:22)
 - checkExecSyncError (node:child_process:470:27)
 - execSync (node:child_process:278:31)
 - oR (B:/~BUN/root/claude.exe:29:3503)
 - <anonymous> (B:/~BUN/root/claude.exe:63:1174)
 - D (B:/~BUN/root/claude.exe:62:19481)
 - uHf (B:/~BUN/root/claude.exe:6165:4940)
 - wm (B:/~BUN/root/claude.exe:6165:8149)
 - <anonymous> (B:/~BUN/root/claude.exe:6165:7917)
 - some (native:1:11)

Steps to Reproduce

During startup, Claude Code runs cygpath -u via Node.js execSync() to convert the Windows working directory path to Unix format. This requires MSYS2 to fork a child process, which
involves copying the parent's memory space and loading DLLs at the exact same addresses. A DLL address space collision — caused by antivirus software, a Windows update, or another
running program occupying the required memory region — prevents the DLLs from initializing,
returning STATUS_DLL_INIT_FAILED (0xC0000142). MSYS2 retries the fork 3 times, all fail, and
Claude Code crashes before reaching the interactive prompt.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.42

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_