gistfile1.txt

class Foo
  has_many :bars
  has_many :bazs
end

class Bar
  belongs_to :foo
  has_many :bazs, :through => :foo
end

class Baz
  belongs_to :foo
end

@foo = Foo.find(1)
@bar = @foo.bars.build(:foo => @foo)

# Why even passing the @foo instance explicitly in,
# I my through association for bazs doesn't get populated?
@foo.bazs => [1, 2, 3]
@bar.bazs => []