继承的struct无法完成父struct的依赖注入

以下代码GetApp2Singleton()后，访问父struct的ServiceImpl1会报空指针，错误panic: runtime error: invalid memory address or nil pointer dereference

// +ioc:autowire=true
// +ioc:autowire:type=singleton
type App struct {
ServiceImpl1 Service singleton:"main.ServiceImpl1"
ServiceImpl2 Service singleton:"main.ServiceImpl2"
}
// +ioc:autowire=true
// +ioc:autowire:type=singleton
type App2 struct {
App
ServiceStruct *ServiceStruct singleton:""
}