Debug Core Data Migration to compare hash values

Question

I read this Post (click) about fixing a nasty core data migration problem.

The author Victor Bogdan wrote that he enabled Data Migration Debug to get the hash values for the entities. What does it mean? Is it possible to enable more debug output for a migration? Or did he wrote a migration process with debug output?

My problem is that I can't get the entity hashes for the mapping model to compare them with the source and destination entity hashes.

I am on XCode 4.5.1 and use iOS6. But I had the same migration problems with older versions.

Answer 1

To enable core data migration debug mode, you will need to add

-com.apple.CoreData.MigrationDebug 1

to the "Arguments Passed on Launch" location in your scheme.

Apple Technical Note TN2124 describes this as well as many other debugging features.