bundle exec rspec grit_spec.rb

/Users/username/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rspec-core-2.0.1/lib/rspec/core/hooks.rb:116:in `run_hook_filtered': undefined method `run_all' for []:Array (NoMethodError)
        from /Users/ktakahashi/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rspec-core-2.0.1/lib/rspec/core/example_group.rb:213:in `eval_after_alls'
        from /Users/ktakahashi/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rspec-core-2.0.1/lib/rspec/core/example_group.rb:236:in `run'
        from /Users/ktakahashi/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rspec-core-2.0.1/lib/rspec/core/command_line.rb:26:in `block (2 levels) in run'
        from /Users/ktakahashi/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rspec-core-2.0.1/lib/rspec/core/command_line.rb:26:in `map'
        from /Users/ktakahashi/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rspec-core-2.0.1/lib/rspec/core/command_line.rb:26:in `block in run'
        from /Users/ktakahashi/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rspec-core-2.0.1/lib/rspec/core/reporter.rb:11:in `report'
        from /Users/ktakahashi/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rspec-core-2.0.1/lib/rspec/core/command_line.rb:23:in `run'
        from /Users/ktakahashi/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rspec-core-2.0.1/lib/rspec/core/runner.rb:55:in `run_in_process'
        from /Users/ktakahashi/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rspec-core-2.0.1/lib/rspec/core/runner.rb:46:in `run'
        from /Users/ktakahashi/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rspec-core-2.0.1/lib/rspec/core/runner.rb:10:in `block in autorun'

bundle install

Fetching gem metadata from https://rubygems.org/.........
Fetching gem metadata from https://rubygems.org/..
Using diff-lcs (1.2.0) 
Using mime-types (1.20.1) 
Using posix-spawn (0.3.6) 
Using grit (2.5.0) 
Using rspec-core (2.0.1) 
Using rspec-expectations (2.0.1) 
Using rspec-mocks (2.0.1) 
Using rspec (2.0.1) 
Using bundler (1.2.3) 
Your bundle is updated! Use `bundle show [gemname]` to see where a bundled gem is installed.

Gemfile

# A sample Gemfile
source "https://rubygems.org"

gem 'rspec'
gem 'grit'

grit_spec.rb

require 'bundler/setup'
Bundler.require

describe Grit::Repo do
  it do
  end
end