ReferenceError __DEV__ is not defined

[Njinou]

Hello, i have tried to use "react-native-maps": "0.27.1" but i am getting an error mentioned above.
I tried to define a global DEV in the app.js but i am getting an error DEV create but never used.
So i would like to know how to create a dev environment or maybe how to integrate "react-native-maps": "0.27.1".
Thanks for your help

[garethx]

Please share a link to the sandbox you're having issues with.