The class _NSZombie_xxxxxxx is implemented as in as well as?

Question

We just started to see these messages appearing in the Xcode debugging area (console) when we go to the view controller where the GMSMapView is created. Everything seems to be working fine, we just don't like these kind of log messages. We do not see them in every run, enough to notice. What to worry about?

objc[15874]: Class _NSZombie_GMSx_PBString is implemented in both ?? and ??. One of the two will be used. Which one is undefined.
objc[15874]: Class _NSZombie_GMSx_PBString is implemented in both ?? and ??. One of the two will be used. Which one is undefined.
objc[15874]: Class _NSZombie_GMSx_PBString is implemented in both ?? and ??. One of the two will be used. Which one is undefined.
objc[15874]: Class _NSZombie_GMSx_PBString is implemented in both ?? and ??. One of the two will be used. Which one is undefined.
objc[15874]: Class _NSZombie_GMSx_PBString is implemented in both ?? and ??. One of the two will be used. Which one is undefined.
objc[15874]: Class _NSZombie_GMSx_GMMResourceResponseProto_Response is implemented in both ?? and ??. One of the two will be used. Which one is undefined.
objc[15874]: Class _NSZombie_GMSx_GMMResourceResponseProto is implemented in both ?? and ??. One of the two will be used. Which one is undefined.
objc[15874]: Class _NSZombie_GMSx_GMMResourceResponseProto is implemented in both ?? and ??. One of the two will be used. Which one is undefined.
objc[15874]: Class _NSZombie_GMSx_GMMResourceResponseProto is implemented in both ?? and ??. One of the two will be used. Which one is undefined.

Any help would be appreciated!

Answer 1

NSZombies turns on. Go to the product scheme → scheme → (CMD + SHIFT +.), And at startup → diagnostics, uncheck the box "Enable zombies."