I did some rails updates, this error came up, google was no help:
cannot load such file -- unicode/unicode_native (LoadError)
So here's the fix, so next time Google will know.
The fix was to fully delete my install of the unicode gem, and reinstall it from scratch.
Somehow the unicode directory was a binary file full of static (or possibly useful NSA intel), so the native bundle could not be found, and I was left holding the blood soaked leash, trying to explain to the police that it's not really blood, it's just the ketchup my dog used to wriggle it's way free and attack those tourist.