Function chdir

crates/vm/src/stdlib/os.rs:1491–1527

(path: OsPath, vm: &VirtualMachine)

    #[pyfunction]
    fn chdir(path: OsPath, vm: &VirtualMachine) -> PyResult<()> {
        env::set_current_dir(&path.path)
            .map_err(|err| OSErrorBuilder::with_filename(&err, path, vm))?;

        #[cfg(windows)]
        {
            // win32_wchdir()

            // On Windows, set the per-drive CWD environment variable (=X:)
            // This is required for GetFullPathNameW to work correctly with drive-relative paths

            use std::os::windows::ffi::OsStrExt;
            use windows_sys::Win32::System::Environment::SetEnvironmentVariableW;

            if let Ok(cwd) = env::current_dir() {
                let cwd_str = cwd.as_os_str();
                let mut cwd_wide: Vec<u16> = cwd_str.encode_wide().collect();

                // Check for UNC-like paths (\\server\share or //server/share)
                // wcsncmp(new_path, L"\\\\", 2) == 0 || wcsncmp(new_path, L"//", 2) == 0
                let is_unc_like_path = cwd_wide.len() >= 2
                    && ((cwd_wide[0] == b'\\' as u16 && cwd_wide[1] == b'\\' as u16)
                        || (cwd_wide[0] == b'/' as u16 && cwd_wide[1] == b'/' as u16));

                if !is_unc_like_path {
                    // Create env var name "=X:" where X is the drive letter
                    let env_name: [u16; 4] = [b'=' as u16, cwd_wide[0], b':' as u16, 0];
                    cwd_wide.push(0); // null-terminate the path
                    unsafe {
                        SetEnvironmentVariableW(env_name.as_ptr(), cwd_wide.as_ptr());
                    }
                }
            }
        }

        Ok(())
    }

    #[pyfunction]
    fn fspath(path: PyObjectRef, vm: &VirtualMachine) -> PyResult<FsPath> {