Core Data Migration - Can't find mapping model for migration

Question

I followed the guide found here: http://www.timisted.net/blog/archive/core-data-migration/ but keep getting \"Can\'t find mapping model for migration\" when I start up the a

Answer 1

Turns out the Mapping Model needs to be part of the .xcdatamodeld package, which is impossible to do within xcode 4. With it in there, it works great.

Note: my mapping file stopped working again, and I found that it was 0KB on disc, so I had to recreate it again and it worked fine after that. I quickly committed it and will see if it disappears again. The problem is that Xcode 4 indexes it or something so it looks fine in xcode but on the file system its empty.

See my comment below for the reason (xcode 4's mapc (map compiler) is broken).

** THIS HAS BEEN FIXED IN THE NEWER XCODEs/SDKs.**