Facebook iOS SDK and iOS6

Question

I'm currently trying to use the Facebook SDK official pod in its 3.14.1 version (also tried 3.9, same result) but I stumble upon an issue.

Here is my code:

self->_session = [[FBSession alloc] initWithAppID:[[self class] facebookAppId]
                                      permissions:self.mandatoryPermissions
                                  urlSchemeSuffix:nil
                               tokenCacheStrategy:[FBSessionTokenCachingStrategy defaultInstance]];


[self->_session openWithBehavior:FBSessionLoginBehaviorWithFallbackToWebView
               completionHandler:^(FBSession *session,
                                       FBSessionState state,
                                       NSError *error)
{
    [self sessionStateChanged:session
                        state:state
                        error:error];
}];

This is greatly inspired from code samples given by facebook : https://developers.facebook.com/docs/facebook-login/ios/v2.0 # Step 1b: Open the session using the custom class

Here is the issue :

dyld: lazy symbol binding failed: Symbol not found: _OSAtomicDecrement32
  Referenced from: /var/mobile/Applications/01DD5CE2-39A9-40AE-A8FC-170F7387D434/Dubb.app/Dubb
  Expected in: /usr/lib/libSystem.B.dylib

dyld: Symbol not found: _OSAtomicDecrement32
  Referenced from: /var/mobile/Applications/01DD5CE2-39A9-40AE-A8FC-170F7387D434/Dubb.app/Dubb
  Expected in: /usr/lib/libSystem.B.dylib

By looking at their SDK code I can't see fallbacks for the OSAtomicDecrement32 in case it doesn't exist, and it in fact exists sstarting with iOS 7.1.

Any advice?

Thanks

Answer 1

I actually understood what happened here after having the same issue on iOS7.0.

The call OSAtomicIncrement32 is defined as its own function on iOS >= 7.1, but it is also defined as an inline call to other functions for iOS < 7.1.

The right definition is used depending on the min deployment target, which for me was set to '7.1' in my podfile. Changing it to:

platform :ios, '7.0'

fixed the issue!