I am getting this error after adding the libxml2.2.dylib file
Linking /Users/Biranchi/Desktop/Funmovies TabBarController/build/Debug-iphonesimulator/funmovi
To add to Graham Heath's answer - which I think deserves more prominence in the thread.
Checking for a missing framework is the quickest and easiest fix to try. Totally non-destructive and probably the cause of these sort of errors for most people. Just browse the list of frameworks for something that looks appropriate and try it. I think many people are fooled because XCode does not flag a problem with a class when you write the code - just when you link it.
My error was: "linker command failed with exit code 1 (use -v to see invocation)" concerning a couple of errors in CoreLocation:
"Undefined symbols for architecture armv7: "_OBJC_CLASS_$_CLLocationManager", referenced from: objc-class-ref in NPTViewController.o"
I added CoreLocation.framework and the job was done.