Not being able to order by includes on Rails3

I have the following expression:

    user.clocks.includes(:runs
=> :user_runs).includes(:users).find_by_id(params[:id])

which seems to work fine. But when I add an orders, like this:

    user.clocks.includes(:runs
=> :user_runs).includes(:users).orders("users.names").find_by_id(params[:id])

it breaks with the following error:

    ActiveRecord::ConfigurationError: Association named 'user_runs'
was not found; perhaps you misspelled it?
    app/controllers/clocks_controller.rb:19:in `show'
        test/functional/clocks_controller_test.rb:21:in
`__bind_1286475263_942556'

Any ideas why?

The model looks like this:

    class Clock < ActiveRecord::Base
      has_and_belongs_to_many :users
      has_many :runs
    end

    class Run < ActiveRecord::Base
      belongs_to :clock
      has_many :user_runs
      has_many :users, :through => :user_runs
    end

    class UserRun < ActiveRecord::Base
      belongs_to :run
      belongs_to :user
    end

Continuing with my investigation I've tried this:

    ubiquitous_user.clocks.includes(:runs
=> :user_runs).find_by_id(params[:id])

and I've noticed the queries it's generating doesn't get user_runs at
all.

I've created a set of tests to try to figure what was going on:

  context "A graph of users, clocks, runs, etc" do
    setup do
      @users = []
      10.times do
        @users << Factory.create(:user)
      end
      @clocks = []
      10.times do
        @clocks << Factory.create(:clock, :users => @users)
      end
      @clocks.each do |clock|
        10.times do
          run = Factory.create :run, :clock => clock
          @users.each do |user|
            Factory.create :user_run, :run => run, :user => user
          end
        end
      end
      @user = @users.first
      @clock = @clocks.first
    end

    should "find a clock" do
      assert_not_nil @user.clocks.find(@clock.id)
    end

    should "find a clock with users" do
      assert_not_nil @user.clocks.includes(:users).find(@clock.id)
    end

    should "find a clock with users and runs" do
      assert_not_nil
@user.clocks.includes(:users, :runs).find(@clock.id)
    end

    should "find a clock with users, runs and user_runs" do
      assert_not_nil @user.clocks.includes(:users, :runs
=> :user_runs).find(@clock.id)
    end

    should "find a clock with users order by users.name" do
      assert_not_nil
@user.clocks.includes(:users).order("users.name").find(@clock.id)
    end

    should "find a clock with users and runs order by users.name" do
      assert_not_nil
@user.clocks.includes(:users, :runs).order("users.name").find(@clock.id)
    end

    should "find a clock with users, runs and user_runs order by
users.name" do
      assert_not_nil @user.clocks.includes(:users, :runs
=> :user_runs).order("users.name").find(@clock.id)
    end
  end

Every test but the last one pass. Is this not a bug?

I am now convinced this is a bug, so I reported it here:
https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/5768

Next time you have a problem with something like this use the to_sql method, it will show you the sql query generated, and you can see what is wrong with what you are doing.