Error when using "tagged_with" together with "includes"

[manuelmeurer]

I noticed an error when "tagged_with" is used together with "includes".
I added a failing test case here: krautcomputing/rocket_tag@e66410b0a9feac87a69aeb14bae90511847a3fcc

The error occurs quite deep in Active Record:

NoMethodError: undefined method `left' for :count:Symbol
# /Users/me/.rbenv/versions/1.9.3-p327-perf/lib/ruby/gems/1.9.1/gems/activerecord-3.2.6/lib/active_record/associations/alias_tracker.rb:64:in `block in initial_count_for'

It seems to have to do with using count in the subquery. See the full stack trace here: https://gist.github.com/4363280

SELECT "taggable_models".* FROM (SELECT count("tags"."id") AS tags_count, taggable_models.* FROM "taggable_models" INNER JOIN "taggings" ON "taggings"."taggable_id" = "taggable_models"."id" AND "taggings"."taggable_type" = 'TaggableModel' INNER JOIN "tags" ON "tags"."id" = "taggings"."tag_id" WHERE "tags"."name" IN ('foo') GROUP BY "taggable_models"."id", "taggable_models"."user_id", "taggable_models"."name", "taggable_models"."type", "taggable_models"."foo" ORDER BY tags_count desc) taggable_models

I will investigate further what may cause this error but all tips are appreciated! :)