I'm getting every logged messages twice from Google services. Tested with standard Google implementation for Google analytics. (This standard configuration code is called once - even if it does not matter anyway)
// Configure tracker from GoogleService-Info.plist.
[[GGLContext sharedInstance] configureWithError:&configureError];
NSAssert(!configureError, @"Error configuring Google services: %@", configureError);
// Optional: configure GAI options.
GAI *gai = [GAI sharedInstance];
gai.trackUncaughtExceptions = YES; // report uncaught exceptions
gai.logger.logLevel = kGAILogLevelVerbose; // remove before app release
2016-10-23 22:06:22.354166 [692:208692] [Firebase/Core][I-COR000001] Configuring the default app.
2016-10-23 22:06:22.354  <Debug> [Firebase/Core][I-COR000001] Configuring the default app.
2016-10-23 22:06:22.374475 [692:208692] <FIRAnalytics/INFO> Firebase Analytics v.3404000 started
2016-10-23 22:06:22.374 [692:] <FIRAnalytics/INFO> Firebase Analytics v.3404000 started
I think this is a case of Xcode 8 being extra verbose. I've seen this happen with Xcode 8 running with an actual device (instead of just the simulator).
I'm pretty sure if you enable the
OS_ACTIVITY_MODE = disable environment variable (as mentioned in this post), this double-logging should go away.
But to be clear, this is just a case of Xcode printing out extra stuff to the console. Firebase analytics itself isn't logging twice the events that it normally does.