cannot convert 'subscriberLoop(std::function<void()>)::<lambda(Redis*, String, String)>' to 'Redis::RedisMsgCallback' {aka 'void (*)(Redis*, String, String)'} 

When I upadte arduino/esp8266 board version to version 3.0.0 or later, this problem appears. The interim solution is to use the older version like 2.7.4. 