envs[i] = kv
	} else {
		i = len(envs)
		envs = append(envs, kv)
	}
	env[key] = i
	runtimeSetenv(key, value)
	return nil
}

func Clearenv() {
	envOnce.Do(copyenv) // prevent copyenv in Getenv/Setenv

	envLock.Lock()
	defer envLock.Unlock()

	for k := range env {
		runtimeUnsetenv(k)
	}
	env = make(map[string]int)
	envs = []string{}
}

func Environ() []string {

}

// Getpagesize and Exit are provided by the runtime.

func Getpagesize() int
func Exit(code int)

// runtimeSetenv and runtimeUnsetenv are provided by the runtime.
func runtimeSetenv(k, v string)

		return err
	}
	e := SetEnvironmentVariable(keyp, v)
	if e != nil {
		return e
	}
	runtimeSetenv(key, value)
	return nil
}

func Unsetenv(key string) error {
	keyp, err := UTF16PtrFromString(key)
	if err != nil {
		return err
	}
	e := SetEnvironmentVariable(keyp, nil)
	if e != nil {
		return e
	}
	runtimeUnsetenv(key)
	return nil
}

func Clearenv() {
	for _, s := range Environ() {

	}
}

//go:linkname syscall_runtimeSetenv syscall.runtimeSetenv
func syscall_runtimeSetenv(key, value string) {
	setenv_c(key, value)
	if key == "GODEBUG" {
		p := new(string)
		*p = value
		godebugEnv.Store(p)
		godebugNotify(true)
	}
}

//go:linkname syscall_runtimeUnsetenv syscall.runtimeUnsetenv
func syscall_runtimeUnsetenv(key string) {
	unsetenv_c(key)