}
	for _, s := range env {
		if len(s) > len(key) && s[len(key)] == '=' && envKeyEqual(s[:len(key)], key) {
			return s[len(key)+1:]
		}
	}
	return ""
}

// envKeyEqual reports whether a == b, with ASCII-only case insensitivity
// on Windows. The two strings must have the same length.
func envKeyEqual(a, b string) bool {
	if GOOS == "windows" { // case insensitive
		for i := 0; i < len(a); i++ {