I'm using rspec-rails 2.11.0 in my app, but when I execute rspec spec/ something wrong happens. This is stack of error:
/Users/diego/.rvm/gems/ruby-1.9.3-head@global/gems/bundler-1.1.4/lib/bundler/runtime.rb:31:in `block in setup': You have already activated rspec-core 2.10.1, but your Gemfile requires rspec-core 2.11.1. Using bundle exec may solve this. (Gem::LoadError)
from /Users/diego/.rvm/gems/ruby-1.9.3-head@global/gems/bundler-1.1.4/lib/bundler/runtime.rb:17:in `setup'
from /Users/diego/.rvm/gems/ruby-1.9.3-head@global/gems/bundler-1.1.4/lib/bundler.rb:107:in `setup'
from /Users/diego/.rvm/gems/ruby-1.9.3-head@global/gems/bundler-1.1.4/lib/bundler/setup.rb:7:in `<top (required)>'
from /Users/diego/.rvm/rubies/ruby-1.9.3-head/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:59:in `require'
from /Users/diego/.rvm/rubies/ruby-1.9.3-head/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:59:in `rescue in require'
from /Users/diego/.rvm/rubies/ruby-1.9.3-head/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:35:in `require'
from /Users/diego/Development/Rails/carros/carros-web/config/boot.rb:6:in `<top (required)>'
from /Users/diego/.rvm/rubies/ruby-1.9.3-head/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /Users/diego/.rvm/rubies/ruby-1.9.3-head/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /Users/diego/Development/Rails/carros/carros-web/config/application.rb:1:in `<top (required)>'
from /Users/diego/.rvm/rubies/ruby-1.9.3-head/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /Users/diego/.rvm/rubies/ruby-1.9.3-head/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /Users/diego/Development/Rails/carros/carros-web/config/environment.rb:2:in `<top (required)>'
from /Users/diego/.rvm/rubies/ruby-1.9.3-head/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /Users/diego/.rvm/rubies/ruby-1.9.3-head/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /Users/diego/Development/Rails/carros/carros-web/spec/spec_helper.rb:3:in `<top (required)>'
from /Users/diego/.rvm/rubies/ruby-1.9.3-head/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /Users/diego/.rvm/rubies/ruby-1.9.3-head/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /Users/diego/Development/Rails/carros/carros-web/spec/models/admin_spec.rb:1:in `<top (required)>'
from /Users/diego/.rvm/gems/ruby-1.9.3-head/gems/rspec-core-2.10.1/lib/rspec/core/configuration.rb:746:in `load'
from /Users/diego/.rvm/gems/ruby-1.9.3-head/gems/rspec-core-2.10.1/lib/rspec/core/configuration.rb:746:in `block in load_spec_files'
from /Users/diego/.rvm/gems/ruby-1.9.3-head/gems/rspec-core-2.10.1/lib/rspec/core/configuration.rb:746:in `map'
from /Users/diego/.rvm/gems/ruby-1.9.3-head/gems/rspec-core-2.10.1/lib/rspec/core/configuration.rb:746:in `load_spec_files'
from /Users/diego/.rvm/gems/ruby-1.9.3-head/gems/rspec-core-2.10.1/lib/rspec/core/command_line.rb:22:in `run'
from /Users/diego/.rvm/gems/ruby-1.9.3-head/gems/rspec-core-2.10.1/lib/rspec/core/runner.rb:69:in `run'
from /Users/diego/.rvm/gems/ruby-1.9.3-head/gems/rspec-core-2.10.1/lib/rspec/core/runner.rb:10:in `block in autorun'
What's is wrong? This is my gem file https://gist.github.com/3280825
What's happening is that your rspec app version is different from the one you have in global env.
And it seems when you execute rspec the one from global is being used.
The way to make it work is to use bundle exec as said from @prusswan wich will execute that command with the app env (with proper gems versions etc..)
Also the error message mentions to try bundle exec