![Use of undeclared identifier 'OWSLegacyContactDiscoveryOperation' · Issue #4135 · signalapp/Signal-iOS · GitHub Use of undeclared identifier 'OWSLegacyContactDiscoveryOperation' · Issue #4135 · signalapp/Signal-iOS · GitHub](https://user-images.githubusercontent.com/47349571/52996484-9641f600-343f-11e9-81d2-64fefbdd0f75.png)
Use of undeclared identifier 'OWSLegacyContactDiscoveryOperation' · Issue #4135 · signalapp/Signal-iOS · GitHub
![Use of undeclared identifier 'ASAuthorizationAppleIDButtonTypeSignUp'; did you mean 'ASAuthorizationAppleIDButtonTypeSignIn'? · Issue #68 · invertase/react-native-apple-authentication · GitHub Use of undeclared identifier 'ASAuthorizationAppleIDButtonTypeSignUp'; did you mean 'ASAuthorizationAppleIDButtonTypeSignIn'? · Issue #68 · invertase/react-native-apple-authentication · GitHub](https://user-images.githubusercontent.com/12025501/79945524-7f15f280-84a0-11ea-9df5-66067805ed44.png)
Use of undeclared identifier 'ASAuthorizationAppleIDButtonTypeSignUp'; did you mean 'ASAuthorizationAppleIDButtonTypeSignIn'? · Issue #68 · invertase/react-native-apple-authentication · GitHub
![c++ - gets() is causing compilation failure with ''use of undeclared identifier 'gets'" error - Stack Overflow c++ - gets() is causing compilation failure with ''use of undeclared identifier 'gets'" error - Stack Overflow](https://i.stack.imgur.com/LiZEA.png)
c++ - gets() is causing compilation failure with ''use of undeclared identifier 'gets'" error - Stack Overflow
![Flipper & RN 0.62 - Build Failed: Use of undeclared identifier 'client' · Issue #28406 · facebook/react-native · GitHub Flipper & RN 0.62 - Build Failed: Use of undeclared identifier 'client' · Issue #28406 · facebook/react-native · GitHub](https://user-images.githubusercontent.com/7311462/77699239-59392300-6fb2-11ea-953f-c507f396bb87.png)
Flipper & RN 0.62 - Build Failed: Use of undeclared identifier 'client' · Issue #28406 · facebook/react-native · GitHub
![Cocoapods Simulator Issue: Use of undeclared identifier 'Phrase' · Issue #33 · phrase/ios-sdk · GitHub Cocoapods Simulator Issue: Use of undeclared identifier 'Phrase' · Issue #33 · phrase/ios-sdk · GitHub](https://user-images.githubusercontent.com/1413291/109195699-22a7f180-779b-11eb-99c1-1871f7339645.png)
Cocoapods Simulator Issue: Use of undeclared identifier 'Phrase' · Issue #33 · phrase/ios-sdk · GitHub
![Use of undeclared identifier FlipperClient · Issue #24 · react-native-community/upgrade-support · GitHub Use of undeclared identifier FlipperClient · Issue #24 · react-native-community/upgrade-support · GitHub](https://user-images.githubusercontent.com/18752429/78028674-ff06dc00-737c-11ea-8028-55f1ca6d037e.png)