can't dup NilClass

gistfile1.bat

 ~/writermortis(master) $sudo bundle exec rake db:seed
rake aborted!
can't dup NilClass
/home/willy/writermortis/db/seeds.rb:9:in `dup'
/home/willy/writermortis/db/seeds.rb:9:in `<top (required)>'
/var/lib/gems/1.9.1/gems/activesupport-3.2.7/lib/active_support/dependencies.rb:245:in `load'
/var/lib/gems/1.9.1/gems/activesupport-3.2.7/lib/active_support/dependencies.rb:245:in `block in load'
/var/lib/gems/1.9.1/gems/activesupport-3.2.7/lib/active_support/dependencies.rb:236:in `load_dependency'
/var/lib/gems/1.9.1/gems/activesupport-3.2.7/lib/active_support/dependencies.rb:245:in `load'
/var/lib/gems/1.9.1/gems/railties-3.2.7/lib/rails/engine.rb:520:in `load_seed'
/var/lib/gems/1.9.1/gems/activerecord-3.2.7/lib/active_record/railties/databases.rake:309:in `block (2 levels) in <top (required)>'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:246:in `call'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:246:in `block in execute'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:241:in `each'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:241:in `execute'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:184:in `block in invoke_with_call_chain'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:177:in `invoke_with_call_chain'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:170:in `invoke'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:143:in `invoke_task'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:101:in `block (2 levels) in top_level'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:101:in `each'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:101:in `block in top_level'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:110:in `run_with_threads'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:95:in `top_level'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:73:in `block in run'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:160:in `standard_exception_handling'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:70:in `run'
Tasks: TOP => db:seed
(See full trace by running task with --trace)