RSpec, Rails 4, Postgres, UUID primary keys: id is null with Rake + RSpec, but is fine in RSpec or console

I'm trying to get up and running with UUID primary keys for a model with Postgres and Rails 4.0.0.rc2, but my specs are failing to create and destroy, yet MyThing.create or MyThing#destroy works fine from the rails console (in both dev and test environments). ...until I run specs, in which case doing either of those things stops working via the console. Thus, it looks like something that happens when I run my specs that alters my DB and prohibits UUID keys from continuing to work.

Halp?

I followed this blog post to generate my migration, thus my schema looks like:

ActiveRecord::Schema.define(version: 20130613174601) do
  # These are extensions that must be enabled in order to support this database
  enable_extension "plpgsql"
  enable_extension "uuid-ossp"

  create_table "growers", id: false, force: true do |t|
    t.uuid     "id",         null: false
    t.string   "name"
    t.string   "code"
    t.datetime "created_at"
    t.datetime "updated_at"
  end
end

Here's the progression of things:

Create: $ rake db:create RAILS_ENV=test

Migrate:

$ rake db:migrate RAILS_ENV=test
==  CreateGrowers: migrating ==================================================
-- enable_extension("uuid-ossp")
   -> 0.0052s
-- create_table(:growers, {:id=>:uuid})
   -> 0.0043s
==  CreateGrowers: migrated (0.0096s) =========================================

Create model object:

$ rails c test
agrian> g = Grower.create name: 'bobo'
   (0.3ms)  BEGIN
  SQL (4.1ms)  INSERT INTO "growers" ("created_at", "name", "updated_at") VALUES ($1, $2, $3) RETURNING "id"  [["created_at", Tue, 18 Jun 2013 20:22:39 UTC +00:00], ["name", "bobo"], ["updated_at", Tue, 18 Jun 2013 20:22:39 UTC +00:00]]
   (0.4ms)  COMMIT
=> #<Grower id: "38f84f39-e52e-4664-b776-4fdfcbd60b09", name: "bobo", code: nil, created_at: "2013-06-18 20:22:39", updated_at: "2013-06-18 20:22:39">

(rejoicing)

Run specs:

$ rake spec
/Users/sloveless/.rbenv/versions/2.0.0-p195/bin/ruby -S rspec ./spec/controllers/api/v1/growers_controller_spec.rb ./spec/helpers/growers_helper_spec.rb ./spec/models/grower_spec.rb ./spec/requests/api/v1/growers_spec.rb ./spec/routing/api/v1/growers_routing_spec.rb
...............FF..........F.*
(other stuff)
Finished in 0.30626 seconds
30 examples, 3 failures, 1 pending

Create model object:

$ rails c test
Loading test environment (Rails 4.0.0.rc2)
agrian> g = Grower.create name: 'bobo'
   (0.4ms)  BEGIN
  SQL (3.5ms)  INSERT INTO "growers" ("created_at", "name", "updated_at") VALUES ($1, $2, $3)  [["created_at", Tue, 18 Jun 2013 20:29:36 UTC +00:00], ["name", "bobo"], ["updated_at", Tue, 18 Jun 2013 20:29:36 UTC +00:00]]
PG::Error: ERROR:  null value in column "id" violates not-null constraint
DETAIL:  Failing row contains (null, bobo, null, 2013-06-18 20:29:36.773391, 2013-06-18 20:29:36.773391).
: INSERT INTO "growers" ("created_at", "name", "updated_at") VALUES ($1, $2, $3)
   (0.2ms)  ROLLBACK
ActiveRecord::StatementInvalid: PG::Error: ERROR:  null value in column "id" violates not-null constraint
DETAIL:  Failing row contains (null, bobo, null, 2013-06-18 20:29:36.773391, 2013-06-18 20:29:36.773391).
: INSERT INTO "growers" ("created_at", "name", "updated_at") VALUES ($1, $2, $3)
from /Users/sloveless/.rbenv/versions/2.0.0-p195/lib/ruby/gems/2.0.0/gems/activerecord-4.0.0.rc2/lib/active_record/connection_adapters/postgresql_adapter.rb:780:in `get_last_result'

(sad face)

Can someone point me in the right direction here as to what might be doing silly stuff with my db?

Update: I can run bin/rspec spec over and over again with success (all my specs pass). If I run rake spec, I get failures, then the next time I run bin/rspec spec I get failures.

Edit: Updated title to reflect rake + rspec problem, not just with rspec.

Solution

I see that rspec-rails/lib/rspec/rails/tasks/rspec.rake defines this for the spec task:

spec_prereq = Rails.configuration.generators.options[:rails][:orm] == :active_record ?  "test:prepare" : :noop
task :noop do; end
task :default => :spec

# other stuff

desc "Run all specs in spec directory (excluding plugin specs)"
RSpec::Core::RakeTask.new(:spec => spec_prereq)

...which runs:

db:load_config
db:test:purge
db:test:load
db:test:load_schema
db:schema:load

I see that, when running rake db:schema:load, I get:

-- enable_extension("plpgsql")
   -> 0.0161s
-- enable_extension("uuid-ossp")
   -> 0.0063s
-- create_table("growers", {:id=>false, :force=>true})
   -> 0.0049s
-- initialize_schema_migrations_table()
   -> 0.0062s

...which is different than when I run the migration:

==  CreateGrowers: migrating ==================================================
-- enable_extension("uuid-ossp")
   -> 0.0050s
-- create_table(:growers, {:id=>:uuid})
   -> 0.0052s
==  CreateGrowers: migrated (0.0103s) =========================================

Thus, it seems to me that the db:schema:load task isn't creating the table with the UUID primary key, thus causing the failures. Seems like a Rails bug??

Update: I guess I'll find out if it's a Rails bug: Issue 11016