TypeError on loading fixtures for integration tests

Functional tests properly load fixtures, but my integration test
chokes:

# def self.create_fixtures(fixtures_directory, table_names,
class_names = {})
# puts("fixtures dir: "+(fixtures_directory.nil? ? "nil" :
fixtures_directory))

It's only nil for my integration tests. I'm on rails edge. Does anyone
know what I'm doing wrong here?

  1) Error:
test_truth(NewSiteTest):
TypeError: can't convert nil into String

/usr/home/daniel/dev/config/../vendor/rails/activerecord/lib/active_record/fixtures.rb:252:in
`join'