ios - CLLocationManager never asks user about location services

I have an IOS 8-only app in which I want to use location
services to obtain the device's latitude and longitude. I think I have everything
implemented correctly, but the app never asks the user if it's okay to use location
services, the CLAuthorizationStatus never changes from
kCLAuthorizationStatusNotDetermined and the CLLocationManager delegate
method

-
            (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading
            *)newHeading 

never
gets called.

Here's the CLLocationManager
defined in the interface file for the
viewcontroller:

__strong
            CLLocationManager
            *locationManager;

Here's
the code in the viewcontroller:

-
            (void)viewDidLoad{
 [super viewDidLoad];

 locationManager
            = [[CLLocationManager alloc] init];

 locationManager.delegate =
            self;
 CLAuthorizationStatus status = [CLLocationManager
            authorizationStatus];
 if (status == kCLAuthorizationStatusNotDetermined)
            {
 [locationManager requestWhenInUseAuthorization];
 }

            [locationManager startUpdatingLocation];
 //... other viewDidLoad
            code
}

The
Info.plist file for the app has an entry for
NSLocationWhenInUseUsageDescription.

Debug
tracing shows that the line

[locationManager
            requestWhenInUseAuthorization];

gets
executed, but the dialog requesting the user to okay location services does not
appear.

Location services in this app worked
correctly under iOS 7 - I'm clearly doing something wrong, or not doing something I need
to do to make it work in iOS 8. But I have dug around looking for insights, and it looks
to me as if I'm doing everything
correctly.

Any ideas and/or
suggestions? Thanks in advance.