Sender Synth example can't build - symbol(s) not found for architecture arm64
问题 I have follow the Sender synth example, with XCode 10.1, Audiokit 4.5.5. But when I try to build it (part Audiobus and Integration), it fails with this error: Undefined symbols for architecture arm64: "_OBJC_CLASS_$_ABPort", referenced from: objc-class-ref in Audiobus.o "_OBJC_CLASS_$_ABAudiobusController", referenced from: objc-class-ref in Audiobus.o "_OBJC_CLASS_$_ABAudioSenderPort", referenced from: objc-class-ref in Audiobus.o "_OBJC_CLASS_$_ABAudioFilterPort", referenced from: objc