quickstart instructions don't work, need 'gem install perftools.rb'

[evanbeard]

On latest rails, I needed to run this to make everything work:

gem install perftools.rb

Until doing this I received the below stacktrace. I recommend telling people to add this to their Gemfiles in the quickstart instructions, this isn't self-evident to people unfamiliar with this project, nor is the below error very clear

PROFILE: interrupts/evictions/bytes = 85/0/32528
Running the command 'bundle exec pprof.rb --gif /private/var/folders/1n/m5whr5kx649c6r8zs65s92gr0000gn/T/rack_perftools_profiler.prof' exited with status 1
/Users/evan/.rvm/gems/ruby-1.9.3-p194/gems/perftools.rb-2.0.0/bin/pprof.rb:3:in `exec': No such file or directory - /Users/evan/.rvm/gems/ruby-1.9.3-p194/gems/perftools.rb-2.0.0/bin/pprof (Errno::ENOENT)
    from /Users/evan/.rvm/gems/ruby-1.9.3-p194/gems/perftools.rb-2.0.0/bin/pprof.rb:3:in `<top (required)>'
    from /Users/evan/.rvm/gems/ruby-1.9.3-p194/bin/pprof.rb:19:in `load'
    from /Users/evan/.rvm/gems/ruby-1.9.3-p194/bin/pprof.rb:19:in `<main>'
    from /Users/evan/.rvm/gems/ruby-1.9.3-p194/bin/ruby_noexec_wrapper:14:in `eval'
    from /Users/evan/.rvm/gems/ruby-1.9.3-p194/bin/ruby_noexec_wrapper:14:in `<main>'