Google Maps iOS SDK Crash in RubyMotion

Question

I have an iOS app built in RubyMotion (using the Promotion framework). I'm trying to load a view which is just a Google Maps view (GMSMapView) - their example even, it loads fine the first time the app is installed on a device or the simulator, but will without fail crash instantly every single time after that; or even if that screen is closed and then re-opened without closing the application.

The code is just Google's "Hello World" example, and I'm banging my head on the wall. My code is below, in addition to trying it as a Promotion Screen I've attempted this by subclassing a fresh UIViewController and get the same error.

My code:

class MapScreen < PM::Screen

  def on_load
    camera = GMSCameraPosition.cameraWithLatitude(-33.868, longitude: 151.2086, zoom: 6)
    mapView = GMSMapView.mapWithFrame(CGRectZero, camera:camera)

    marker = GMSMarker.new
    marker.position = camera.target
    marker.snippet = "Hello World"
    marker.appearAnimation = 1
    marker.map = mapView

    mapView.delegate = self
    # self.view = mapView
    self.view.addSubview(mapView)
  end

end

And here's the relevant parts of the crashlog:

Crashed Thread:        2  Dispatch queue: com.google.Maps.TileDataCacheQueue

Exception Type:        EXC_BAD_ACCESS (SIGSEGV)
Exception Codes:       KERN_INVALID_ADDRESS at 0x0000656d69546e77

Thread 0:: Dispatch queue: NSPersistentStoreCoordinator 0x11c34be80
0   libobjc.A.dylib                 0x000000010177302c objc_msgSend + 44
1   CoreData                        0x00000001020e09d3 -[NSSQLModel _generateModel:error:] + 1363
2   CoreData                        0x0000000101fc5481 -[NSSQLModel initWithManagedObjectModel:configurationName:retainHashHack:brokenHashVersion:] + 305
3   CoreData                        0x0000000101fc4823 -[NSSQLCore initWithPersistentStoreCoordinator:configurationName:URL:options:] + 819
4   CoreData                        0x00000001020ac77d __91-[NSPersistentStoreCoordinator addPersistentStoreWithType:configuration:URL:options:error:]_block_invoke + 1069
5   CoreData                        0x00000001020b9c30 gutsOfBlockToNSPersistentStoreCoordinatorPerform + 192
6   libdispatch.dylib               0x0000000106e50964 _dispatch_client_callout + 8
7   libdispatch.dylib               0x0000000106e39fca _dispatch_barrier_sync_f_invoke + 76
8   CoreData                        0x00000001020ab245 _perform + 197
9   CoreData                        0x0000000101fc42e1 -[NSPersistentStoreCoordinator addPersistentStoreWithType:configuration:URL:options:error:] + 337
10  com.mwc.mwcpa2015               0x000000010002a341 -[GMSCacheStorage initWithName:modelBundle:modelName:directory:reset:] + 669
11  com.mwc.mwcpa2015               0x00000001001c3574 -[GMSServices initWithDisplayLink:resourceCache:] + 3617
12  com.mwc.mwcpa2015               0x00000001001c1d1f __43-[GMSAsyncInitServices sharedInitWithSync:]_block_invoke_2 + 105
13  com.mwc.mwcpa2015               0x00000001001c1c89 __43-[GMSAsyncInitServices sharedInitWithSync:]_block_invoke + 354
14  com.mwc.mwcpa2015               0x00000001001c1ae3 -[GMSAsyncInitServices sharedInitWithSync:] + 326
15  com.mwc.mwcpa2015               0x00000001001c191b -[GMSAsyncInitServices initSync] + 69
16  com.mwc.mwcpa2015               0x00000001001c25e0 +[GMSServices sharedServicesSync] + 183
17  com.mwc.mwcpa2015               0x00000001001b7814 -[GMSMapView sharedInitWithServices:camera:] + 162
18  com.mwc.mwcpa2015               0x00000001001b7112 -[GMSMapView initWithFrame:camera:] + 121
19  com.mwc.mwcpa2015               0x00000001001b6fb1 +[GMSMapView mapWithFrame:camera:] + 104


Thread 2 Crashed:: Dispatch queue: com.google.Maps.TileDataCacheQueue
0   libobjc.A.dylib                 0x000000010175bcc1 class_getSuperclass + 11
1   com.mwc.mwcpa2015               0x00000001009e0af6 rb_objc_convert_immediate + 118
2   com.mwc.mwcpa2015               0x00000001002b14a9 vm_ocval_to_rval + 153
3   com.mwc.mwcpa2015               0x00000001002fee18 __unnamed_71 + 24
4   com.mwc.mwcpa2015               0x000000010003010e __47-[GMSTileDataCache startWithCompletionHandler:]_block_invoke57 + 639
5   com.mwc.mwcpa2015               0x000000010003496b -[GMSTileDataCache fetchTilesImmediateWithPredicate:sortDescriptor:completionHandler:] + 351
6   com.mwc.mwcpa2015               0x000000010002fd78 __47-[GMSTileDataCache startWithCompletionHandler:]_block_invoke + 412
7   libdispatch.dylib               0x0000000106e35f16 _dispatch_call_block_and_release + 12
8   libdispatch.dylib               0x0000000106e50964 _dispatch_client_callout + 8
9   libdispatch.dylib               0x0000000106e3acb4 _dispatch_queue_drain + 435
10  libdispatch.dylib               0x0000000106e3a9a3 _dispatch_queue_invoke + 217
11  libdispatch.dylib               0x0000000106e3cc85 _dispatch_root_queue_drain + 534
12  libdispatch.dylib               0x0000000106e3dd59 _dispatch_worker_thread3 + 98
13  libsystem_pthread.dylib         0x00000001071b9637 _pthread_wqthread + 729
14  libsystem_pthread.dylib         0x00000001071b740d start_wqthread + 13

This is driving me crazy, any help would be greatly appreciated!

Answer 1

Your marker is losing its reference and getting garbage collected. Try an ivar:

class MapScreen < PM::Screen

  def on_load
    camera = GMSCameraPosition.cameraWithLatitude(-33.868, longitude: 151.2086, zoom: 6)
    mapView = GMSMapView.mapWithFrame(CGRectZero, camera:camera)

    @marker = GMSMarker.new
    @marker.position = camera.target
    @marker.snippet = "Hello World"
    @marker.appearAnimation = 1
    @marker.map = mapView

    mapView.delegate = self
    # self.view = mapView
    self.view.addSubview(mapView)
  end

end