If you are using bundler, then the capistrano task should be:
namespace :deploy do
desc "reload the database with seed data"
task :seed do
run "cd #{current_path}; bundle exec rake db:seed RAILS_ENV=#{rails_env}"
end
end
and it might be placed in a separate file, such as lib/deploy/seed.rb
and included in your deploy.rb file using following command:
load 'lib/deploy/seed'