3 x Build Failed

[thinklog]

Hi.
Alas, it didn't compile. I get the following errors:
** BUILD FAILED **

The following build commands failed:
CompileC /Users/thinklog/Development/react_native/reactnative-jwts/ios/build/Build/Intermediates/RCTLinking.build/Debug-iphonesimulator/RCTLinking.build/Objects-normal/x86_64/RCTLinkingManager.o RCTLinkingManager.m normal x86_64 objective-c com.apple.compilers.llvm.clang.1_0.compiler
CompileC /Users/thinklog/Development/react_native/reactnative-jwts/ios/build/Build/Intermediates/A0RNLock.build/Debug-iphonesimulator/A0RNLock.build/Objects-normal/x86_64/A0ObjectSerializer.o A0RNLock/Core/A0ObjectSerializer.m normal x86_64 objective-c com.apple.compilers.llvm.clang.1_0.compiler
CompileC /Users/thinklog/Development/react_native/reactnative-jwts/ios/build/Build/Intermediates/RCTWebSocket.build/Debug-iphonesimulator/RCTWebSocket.build/Objects-normal/x86_64/RCTWebSocketExecutor.o RCTWebSocketExecutor.m normal x86_64 objective-c com.apple.compilers.llvm.clang.1_0.compiler
(3 failures)

Any ideas what's happening and why, and how to correct it would be much appreciated.
Thanks.