I'm attempting to migrate a Core Data SQLite store in my Mac OS X Leopard app. The migration itself is simple, there's just a couple of changes between the model versions, and there's one custom NSEntityMigrationPolicy
that does a little bit of string manipulation.
99% of the time, this works perfectly. However, occasionally it crashes with EXC_BAD_ACCESS
in objc_assign_strongCast
under migrateStoreFromURL:
type:
options:
withMappingModel:
toDestinationURL:
destinationType:
destinationOptions:
error:
.
At this point, my custom migration policy hasn't been invoked, so I don't think that's causing it. I've also triple checked my mapping model file, and all seems to be well.
The kicker is that if I simply try to migrate the same file again, it normally works fine. I've no idea where to start debugging this, so any pointers would be welcome!