Core Data Migration - “Can't add source store” error

Question

In my iPhone app I'm using Core Data and I've made changes to my data model that cannot be automatically migrated over (i.e. added new relationships). I added the data model version (Design -> Data Model -> Add Model Version) and applied my new data model changes to the new version 2. I then created a mapping object model and set the Source and Destination models to their correct data models (old and new respectively).

When I run the app and call the persistentStoreCoordinator, my app barfs with the following:

2010-02-27 02:40:30.922 XXXX[73578:20b] Unresolved error Error Domain=NSCocoaErrorDomain Code=134110 UserInfo=0xfc2240 "Operation could not be completed. (Cocoa error 134110.)", { NSUnderlyingError = Error Domain=NSCocoaErrorDomain Code=134130 UserInfo=0xfbb3a0 "Operation could not be completed. (Cocoa error 134130.)"; reason = "Can't add source store"; }

FWIW (not much i think) I've also made the usual code changes in persistentStoreCoordinator to use the NSMigratePersistentStoresAutomaticallyOption and NSInferMappingModelAutomaticallyOption (for future data model changes that can be automatically migrated). More relevantly, my managedObjectModel is created by calling initWithContentsOfURL where the file/resource type is "momd".

I've tried updating both the source and destination model in the mapping model (Design -> Mapping Model -> Update XXX Model) as well as deleted the mapping model and recreated it. I've cleaned and re-built but all to no avail. I still get the above error message.

Any pointers/thoughts on how I can further debug or resolve this problem please? I haven't posted any code snippets because this feels much more like a build environment issue (and my code is very standard - just the usual core data code to handle migrations using a mapping model but I'm happy to show the code if it helps).

Appreciate any help.

Thanks

Answer 1

Ok, this is now fixed.

I (a) deleted and then recreated my managed object model classes, (b) deleted and then recreated the mapping model and then finally I (c) deleted the iphone project under the users/xxx/Library/Application Support/iPhone Simulator/User/Applications.

Given I previously tried and failed with doing just (a) and (b), I suspect it was (c) which fixed the problem.