derailed_benchmark error

gistfile1.txt

Yis-MacBook-Pro:halo yifu$ rake -f perf.rake perf:ram_over_time TEST_COUNT=10 --trace
** Invoke perf:ram_over_time (first_time)
** Invoke perf:setup (first_time)
** Execute perf:setup
Booting: production
** Execute perf:ram_over_time
PID: 7124
199.3203125
rake aborted!
Bad request:
/Users/yifu/.rvm/gems/ruby-2.2.0/gems/derailed_benchmarks-0.0.0/lib/derailed_benchmarks/tasks.rb:56:in `call_app'
/Users/yifu/.rvm/gems/ruby-2.2.0/gems/derailed_benchmarks-0.0.0/lib/derailed_benchmarks/tasks.rb:207:in `block (3 levels) in <top (required)>'
/Users/yifu/.rvm/gems/ruby-2.2.0/gems/derailed_benchmarks-0.0.0/lib/derailed_benchmarks/tasks.rb:206:in `times'
/Users/yifu/.rvm/gems/ruby-2.2.0/gems/derailed_benchmarks-0.0.0/lib/derailed_benchmarks/tasks.rb:206:in `block (2 levels) in <top (required)>'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/task.rb:240:in `call'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/task.rb:240:in `block in execute'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/task.rb:235:in `each'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/task.rb:235:in `execute'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/task.rb:179:in `block in invoke_with_call_chain'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/task.rb:172:in `invoke_with_call_chain'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/task.rb:165:in `invoke'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/application.rb:150:in `invoke_task'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/application.rb:106:in `block (2 levels) in top_level'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/application.rb:106:in `each'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/application.rb:106:in `block in top_level'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/application.rb:115:in `run_with_threads'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/application.rb:100:in `top_level'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/application.rb:78:in `block in run'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/application.rb:176:in `standard_exception_handling'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/rake/application.rb:75:in `run'
/Users/yifu/.rvm/rubies/ruby-2.2.0/lib/ruby/gems/2.2.0/gems/rake-10.4.2/bin/rake:33:in `<top (required)>'
/Users/yifu/.rvm/gems/ruby-2.2.0/bin/rake:23:in `load'
/Users/yifu/.rvm/gems/ruby-2.2.0/bin/rake:23:in `<main>'
/Users/yifu/.rvm/gems/ruby-2.2.0/bin/ruby_executable_hooks:15:in `eval'
/Users/yifu/.rvm/gems/ruby-2.2.0/bin/ruby_executable_hooks:15:in `<main>'
Tasks: TOP => perf:ram_over_time