sunspot/sunspot — pull request #373 by jassa (2013-03-05 01:13:16+00:00)
Title: Let Rails handle defaults for custom primary keys

Rails offers support for custom primary_keys, e.g. UUID.
See https://github.com/rails/rails/pull/7987

The `start` option default always expected an integer primary key,
which causes `find_in_batches` to crash.