At first I imported Google Analytics iOS SDK directly and everything worked. Then I started using cocoa pods to manage all of my external libraries and getting this error.
Undefined symbols for architecture i386:
"_OBJC_CLASS_$_GAI", referenced from:
objc-class-ref in AppDelegate.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Looks like Cocoa Pods isn't importing required libraries?