Actually this is working for me now. I did have a bug in my original migration policy, and at some point in my regression I changed something which resulted in my migration policy class not getting loaded by the application and didn't notice because the reported error was the same. Cheerio, Michael Johnston lastobelus@mac.com On 27-Jan-10, at 10:35 PM, Michael Johnston wrote:

Hi,

I'm having trouble implementing a NSEntityMigrationPolicy. Has anyone used subclasses of NSEntityMigrationPolicy in macruby successfully?

I've narrowed it down to the empty macruby implementation, which looks like this:

{{{

class V3RecipeIngredientToIngredient < NSEntityMigrationPolicy def createDestinationInstancesForSourceInstance(source, entityMapping:mapping, manager:manager, error:error) return true end

def createRelationshipsForDestinationInstance(dInstance, entityMapping:mapping, manager:manager, error:error) true end end

}}}

when I run this (and do a addPersistentStoreWithType with NSMigratePersistentStoresAutomaticallyOption) I get:

#<Class:0x10145fc80>: An error occured during persistent store migration. userInfo: {"NSUnderlyingException"=>#<_NSCoreDataException: 0x8002d8840>}

the _NSCoreDataException does not seem to have any message or other chain of errors.

the corresponding Objective C empty implementation works fine:

{{{ - (BOOL)createDestinationInstancesForSourceInstance: (NSManagedObject*)source entityMapping: (NSEntityMapping*)mapping manager: (NSMigrationManager*)manager error:(NSError**)error { return YES; } }}}

Is there any way to get more detail on how/why it is failing?

Cheerio,

Michael Johnston lastobelus@mac.com

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