objective c - Xcode build failure "Undefined symbols for architecture x86_64" -

an xcode beginner's question:

it first experience xcode 4.6.3.

i trying write simple console program, searches paired bt devices , prints them nslog.

it builds following error:

undefined symbols architecture x86_64:   "_objc_class_$_iobluetoothdevice", referenced from:       objc-class-ref in main.o ld: symbol(s) not found architecture x86_64 clang: error: linker command failed exit code 1 (use -v see invocation) 

i searched crazy. common problem should reference file, of header files imported , no implementation (*.m-file) found linker. iobluetooth library however, standard framework foundation framework.

what missing in above statement?

i have tried building 32-bit machine (build fails again). linker error, have no idea, relates, except there issue finding implementation iobluetoothdevice, on both x86 , x64 architecture, while header files standard included framework, called iobluetooth?

for information main code "main.m" being:

#import <foundation/foundation.h> #import <iobluetooth/objc/iobluetoothdevice.h>          // note import bluetooth #import <iobluetooth/objc/iobluetoothdeviceinquiry.h>   // note import bluetooth   int main(int argc, const char * argv[]) {     @autoreleasepool {         iobluetoothdevice *currentdevice;         nsarray *devices = [ iobluetoothdevice paireddevices];           (id currentdevice in devices){           nslog(@"%i : %@",[ currentdevice classofdevice ], [ currentdevice name ]);             }     }     return 0; } 

thanks or pointers right direction.

it looks missing including iobluetooth.framework in project. can add by:

-clicking on project in upper left of left pane (the blue icon).

-in middle pane, click on build phases tab.

-under "link binary libraries", click on plus button.

-find iobluetooth.framework list , hit add.

this make sure iobluetooth.framework definitions found linker. can see framework member of target clicking on framework in left pane , seeing framework's target membership in right pane (note i've moved framework under frameworks group organization purposes):