Class _NSZombie_xxxxxxx is implemented in both ?? and?

Question

We just started seeing these messages appearing in the debug area (console) of Xcode when we navigate to the view controller where the GMSMapView gets created. Everything seems to be working fine, we just don't like messages like this in the logs. We don't see them every run, just enough to take notice. Is this something 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 is turned on. Go to product -> scheme -> edit scheme (CMD+SHIFT+.) and under run -> diagnostics uncheck "Enable Zombies".