Error when running a scenario with spork enabled

[corroded]

Running: /Users/eumir/.rvm/rubies/ruby-1.9.2-p180/bin/ruby /Users/eumir/rails_apps/kiseki/script/cucumber /Users/eumir/rails_apps/kiseki/features/users/generate_character.feature --format=html 
Using the default profile... 
Disabling profiles... 
Exception encountered: # backtrace: 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/cucumber-1.0.0/lib/cucumber/cli/configuration.rb:194:in `arrange_formats' 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/cucumber-1.0.0/lib/cucumber/cli/configuration.rb:26:in `parse!' 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/cucumber-1.0.0/lib/cucumber/cli/main.rb:54:in `configuration' 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/cucumber-1.0.0/lib/cucumber/cli/main.rb:62:in `run_drb_client' 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/cucumber-1.0.0/lib/cucumber/cli/main.rb:34:in `execute!' 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/spork-0.8.5/lib/spork/test_framework/cucumber.rb:22:in `run_tests' 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/spork-0.8.5/lib/spork/run_strategy/forking.rb:13:in `block in run' 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/spork-0.8.5/lib/spork/forker.rb:21:in `block in initialize' 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/spork-0.8.5/lib/spork/forker.rb:18:in `fork' 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/spork-0.8.5/lib/spork/forker.rb:18:in `initialize' 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/spork-0.8.5/lib/spork/run_strategy/forking.rb:9:in `new' 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/spork-0.8.5/lib/spork/run_strategy/forking.rb:9:in `run' 
/Users/eumir/.rvm/gems/ruby-1.9.2-p180@kiseki/gems/spork-0.8.5/lib/spork/server.rb:47:in `run' 
/Users/eumir/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/drb/drb.rb:1558:in `perform_without_block' 
/Users/eumir/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/drb/drb.rb:1518:in `perform' 
/Users/eumir/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/drb/drb.rb:1592:in `block (2 levels) in main_loop'
/Users/eumir/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/drb/drb.rb:1588:in `loop' 
/Users/eumir/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/drb/drb.rb:1588:in `block in main_loop' true

Running spork cuc and cucumber in the command line doesn't give this error so I guess it's a path issue?