cannot remove Object::ClassMethods

[jch]

When running:

$ RAILS_ENV=test rake hydra:spec --trace
(in /Users/jch/projects/pharmmd)
rake aborted!
cannot remove Object::ClassMethods
/Users/jch/.rvm/gems/ree-1.8.7-2010.02/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:603:in `remove_const'
/Users/jch/.rvm/gems/ree-1.8.7-2010.02/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:603:in `remove_constant'
/Users/jch/.rvm/gems/ree-1.8.7-2010.02/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:603:in `instance_eval'
/Users/jch/.rvm/gems/ree-1.8.7-2010.02/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:603:in `remove_constant'
/Users/jch/.rvm/gems/ree-1.8.7-2010.02/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:549:in `new_constants_in'
/Users/jch/.rvm/gems/ree-1.8.7-2010.02/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:549:in `each'
/Users/jch/.rvm/gems/ree-1.8.7-2010.02/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:549:in `new_constants_in'
/Users/jch/.rvm/gems/ree-1.8.7-2010.02/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:156:in `require'
/Users/jch/projects/my_project/Rakefile:20
/Users/jch/.rvm/gems/ree-1.8.7-2010.02/gems/hydra-0.22.2/lib/hydra/tasks.rb:79:in `initialize'

Rakefile line 20 attempts to load spec/spec_helper, which in turn fails when trying to load config/environment.rb

require 'hydra'
require 'hydra/tasks'
# set up a new hydra testing task named 'hydra:spec' run with "rake hydra:spec"
Hydra::TestTask.new('hydra:spec') do |t|
  require 'spec/spec_helper'  # fails here after trying to load config/environment.rb
  t.add_files 'spec/**/*_spec.rb'
end

The app is on Rails version 2.3.4. I tried this using my system ruby (1.8.7) and also got the same error. It runs fine if I do a normal 'rake spec'. Let me know if any other details would be helpful.