2-1 stable branch broken

here's a stack trace from a breaking app - this app runs rake fine against rails 2.0 and an older edge version of Rails (~month old)

** Invoke default (first_time)

** Invoke test (first_time)

** Invoke test:helpers (first_time)

** Invoke db:test:prepare (first_time)

** Invoke environment (first_time)

** Execute environment

rake aborted!

uninitialized constant ActiveSupport::Dependencies

/Users/rsanheim/src/relevance/fizmo/vendor/rails/activesupport/lib/active_support/dependencies.rb:278:in `load_missing_constant'

/Users/rsanheim/src/relevance/fizmo/vendor/rails/activesupport/lib/active_support/dependencies.rb:467:in `const_missing'

/Users/rsanheim/src/relevance/fizmo/config/../vendor/rails/railties/lib/initializer.rb:206:in `set_autoload_paths'

/Users/rsanheim/src/relevance/fizmo/config/../vendor/rails/railties/lib/initializer.rb:117:in `process'

/Users/rsanheim/src/relevance/fizmo/config/../vendor/rails/railties/lib/initializer.rb:96:in `send'

/Users/rsanheim/src/relevance/fizmo/config/../vendor/rails/railties/lib/initializer.rb:96:in `run'

/Users/rsanheim/src/relevance/fizmo/config/environment.rb:7

/opt/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require'

/opt/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'

/Users/rsanheim/src/relevance/fizmo/vendor/rails/activesupport/lib/active_support/dependencies.rb:509:in `require'

/Users/rsanheim/src/relevance/fizmo/vendor/rails/activesupport/lib/active_support/dependencies.rb:354:in `new_constants_in'

/Users/rsanheim/src/relevance/fizmo/vendor/rails/activesupport/lib/active_support/dependencies.rb:509:in `require'

/Users/rsanheim/src/relevance/fizmo/vendor/rails/railties/lib/tasks/misc.rake:3

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:546:in `call'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:546:in `execute'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:541:in `each'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:541:in `execute'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:508:in `invoke_with_call_chain'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:501:in `synchronize'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:501:in `invoke_with_call_chain'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:518:in `invoke_prerequisites'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:1183:in `each'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:1183:in `send'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:1183:in `each'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:515:in `invoke_prerequisites'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:507:in `invoke_with_call_chain'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:501:in `synchronize'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:501:in `invoke_with_call_chain'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:518:in `invoke_prerequisites'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:1183:in `each'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:1183:in `send'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:1183:in `each'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:515:in `invoke_prerequisites'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:507:in `invoke_with_call_chain'

/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.1/lib/rake.rb:501:in `synchronize'

Tests fail too:

 1) Error:
test_should_create_generator_source_for_each_directory_in_plugin_paths(GeneratorLookupTest):
NameError: uninitialized constant ActiveSupport::Dependencies
    ./test/../../activesupport/lib/active_support/dependencies.rb:278:in `load_missing_constant'
    ./test/../../activesupport/lib/active_support/dependencies.rb:467:in `const_missing'
    ./test/../lib/rails/plugin/loader.rb:48:in `add_plugin_load_paths'
    ./test/../lib/rails/plugin/loader.rb:46:in `each'
    ./test/../lib/rails/plugin/loader.rb:46:in `add_plugin_load_paths'
    ./test/../lib/rails/plugin/loader.rb:45:in `each'
    ./test/../lib/rails/plugin/loader.rb:45:in `add_plugin_load_paths'
    ./test/../lib/initializer.rb:238:in `add_plugin_load_paths'
    test/generator_lookup_test.rb:11:in `setup'

  2) Error:
test_should_load_from_all_plugin_paths(GeneratorLookupTest):
NameError: uninitialized constant ActiveSupport::Dependencies
    ./test/../../activesupport/lib/active_support/dependencies.rb:278:in `load_missing_constant'
    ./test/../../activesupport/lib/active_support/dependencies.rb:467:in `const_missing'
    ./test/../lib/rails/plugin/loader.rb:48:in `add_plugin_load_paths'
    ./test/../lib/rails/plugin/loader.rb:46:in `each'
    ./test/../lib/rails/plugin/loader.rb:46:in `add_plugin_load_paths'
    ./test/../lib/rails/plugin/loader.rb:45:in `each'
    ./test/../lib/rails/plugin/loader.rb:45:in `add_plugin_load_paths'
    ./test/../lib/initializer.rb:238:in `add_plugin_load_paths'
    test/generator_lookup_test.rb:11:in `setup'

  3) Error:
test_should_preserve_order_in_usage_message(GeneratorLookupTest):
NameError: uninitialized constant ActiveSupport::Dependencies
    ./test/../../activesupport/lib/active_support/dependencies.rb:278:in `load_missing_constant'
    ./test/../../activesupport/lib/active_support/dependencies.rb:467:in `const_missing'
    ./test/../lib/rails/plugin/loader.rb:48:in `add_plugin_load_paths'
    ./test/../lib/rails/plugin/loader.rb:46:in `each'
    ./test/../lib/rails/plugin/loader.rb:46:in `add_plugin_load_paths'
    ./test/../lib/rails/plugin/loader.rb:45:in `each'
    ./test/../lib/rails/plugin/loader.rb:45:in `add_plugin_load_paths'
    ./test/../lib/initializer.rb:238:in `add_plugin_load_paths'
    test/generator_lookup_test.rb:11:in `setup'