scope on habtm completely fucked when including?

self_contained.rb

begin
  require 'bundler/inline'
rescue LoadError => e
  $stderr.puts 'Bundler version 1.10 or later is required. Please update your Bundler'
  raise e
end

gemfile(true) do
  source 'https://rubygems.org'
  gem 'rails', github: 'rails/rails'
  gem 'arel', github: 'rails/arel'
  gem 'rack', github: 'rack/rack'
  gem 'sprockets', github: 'rails/sprockets'
  gem 'sprockets-rails', github: 'rails/sprockets-rails'
  gem 'sass-rails', github: 'rails/sass-rails'
  gem 'sqlite3'
end

require 'active_record'
require 'minitest/autorun'
require 'logger'

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ':memory:')
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :students do |t|
  end
 
  create_table :groups do |t|
    t.string  :name
  end

  create_table :groups_students, :id => false do |t|
    t.integer :group_id,   :null => false
    t.integer :student_id, :null => false
  end
end

class Student < ActiveRecord::Base
  has_and_belongs_to_many :groups, ->{ where(name: 'Foo') }
end
 
class Group < ActiveRecord::Base
  has_and_belongs_to_many :students
end
 
class BugTest < Minitest::Test
  def test_association
    g = Group.new
    g.name = "Foo"
    g.save!

    s = Student.new
    s.groups << g
    s.save!

    Student.includes(:groups).where(id: 1).to_a
  end
end