error unrecognized selector sent to class while adding Google Map SDK to iOS6 - dictionary

Question

This is a single view application and I followed the instruction given at link
https://developers.google.com/maps/documentation/ios/start
for adding google map SDK to iOS6.
ERROR Is:
unrecognized selector sent to class 0xe2b0
2013-02-07 15:21:29.788 mapApp[2061:12e03] *** Terminating app due to uncaught exception
'NSInvalidArgumentException', reason: '+[GMSCameraPosition
cameraWithLatitude:longitude:zoom:]: unrecognized selector sent to class 0xe2b0'
AppDelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
self.viewController = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
self.window.rootViewController = self.viewController;
//initializing google map api key
[GMSServices provideAPIKey:#"google's api key goes here"];
[self.window makeKeyAndVisible];
return YES;
}
ViewController.m
#import "ViewController.h"
#import <GoogleMaps/GoogleMaps.h>
#interface ViewController ()
#end
#implementation ViewController
{
GMSMapView *mapView;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
GMSCameraPosition *cam = [GMSCameraPosition cameraWithLatitude:13.0245231
longitude:77.64072579999993
zoom:6];
mapView = [GMSMapView mapWithFrame:CGRectZero camera:cam];
mapView.myLocationEnabled = YES;
GMSMarkerOptions *options = [[GMSMarkerOptions alloc]init ];
options.position = CLLocationCoordinate2DMake(13.025738,77.637809);
options.title = #"ensign";
options.snippet = #"kalyan nagar";
[mapView addMarkerWithOptions:options];
}
main.m
#import <UIKit/UIKit.h>
#import <GoogleMaps/GoogleMaps.h>
int main(int argc, char *argv[])
{
#autoreleasepool {
return UIApplicationMain(argc, argv,nil, NSStringFromClass([AppDelegate class]));
}
}
While tracking the error it is showing at the return statement in main.m which comes from the method -viewDidLoad after executing the first line
GMSCameraPosition *cam = [GMSCameraPosition cameraWithLatitude:13.0245231
longitude:77.64072579999993
zoom:6];
It escapes the rest of the lines.

Answer 1

Did you add -ObjC to the Other Linker Flags, in step 7 of the instructions?
--
Extra information edit: note that -ObjC is case sensitive.

Answer 2

I had the same problem. Make sure you add the -ObjC flag to the 'Build Settings' of your 'Target' and NOT 'Project'.
P.S. Adding it in both places doesn't break it either.

Answer 3

Google Doc says
Choose your project, rather than a specific target, and open the Build Settings tab.
In the Other Linker Flags section, add -ObjC. If these settings are not visible, change the filter in the Build Settings bar from Basic to All.
Sometimes this is wrong....
I had to add the linker flag to the target as well, to get it to work. This should help someone