# CMake Error: Path conversion from "C:\Users\User\project" to "/cygdrive/c/Users/User/project" failed.

- **ID:** `cmake/cygwin-path-conversion-failed`
- **Domain:** cmake
- **Category:** system_error
- **Verification:** ai_generated
- **Fix Rate:** 85%

## Root Cause

Cygwin environment cannot convert Windows-style paths to Cygwin paths due to missing cygpath utility or misconfigured environment.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.20 | active | — | — |
| 3.24 | active | — | — |
| 3.28 | active | — | — |

## Workarounds

1. **Ensure cygpath is in PATH: run `which cygpath` in Cygwin terminal. If missing, reinstall Cygwin with 'cygwin' package.** (85% success)
   ```
   Ensure cygpath is in PATH: run `which cygpath` in Cygwin terminal. If missing, reinstall Cygwin with 'cygwin' package.
   ```
2. **Use native Windows CMake (not Cygwin version) by invoking `cmake.exe` from cmd or PowerShell.** (90% success)
   ```
   Use native Windows CMake (not Cygwin version) by invoking `cmake.exe` from cmd or PowerShell.
   ```

## Dead Ends

- **Manually set the path in CMakeLists.txt using absolute Windows path.** — Cygwin's CMake still expects Cygwin paths internally, causing further errors. (60% fail)
- **Reinstall Cygwin with default packages only.** — Cygwin's cygpath is part of the base install; missing it indicates a corrupted environment. (40% fail)