Rake aborted: could not find rspec

Question

I'm trying to work through the Ruby course from TestFirst.org. It requires you to navigate to the folder containing the exercise, run rake, and then correct any errors in the source code it uncovers. When I run rake in the folder for the first exercise it gives this error:

rake aborted!
Could not find rspec (~> 2) amongst [diff-lcs-1.2.5, rspec-3.0.0, rspec-core-3.0.0,
rspec- expectations-3.0.0, rspec-mocks-3.0.1, rspec-support-3.0.0]
/home/jayson/Desktop/learn_ruby/Rakefile:2:in `<top (required)>'
(See full trace by running task with --trace)

Does this means it will only work with an old version of rspec or something else? Running rake with --trace gives me:

rake aborted!
Could not find rspec (~> 2) amongst [diff-lcs-1.2.5, rspec-3.0.0, 
rspec-core-3.0.0, rspec-expectations-3.0.0, rspec-mocks-3.0.1, rspec-support-3.0.0]
/usr/lib/ruby/1.9.1/rubygems/dependency.rb:247:in `to_specs'
/usr/lib/ruby/1.9.1/rubygems/dependency.rb:256:in `to_spec'
/usr/lib/ruby/1.9.1/rubygems.rb:1231:in `gem'
/home/jayson/Desktop/learn_ruby/Rakefile:2:in `<top (required)>'
/usr/lib/ruby/vendor_ruby/rake/rake_module.rb:25:in `load'
/usr/lib/ruby/vendor_ruby/rake/rake_module.rb:25:in `load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:589:in `raw_load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:89:in `block in load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:160:in `standard_exception_handling'
/usr/lib/ruby/vendor_ruby/rake/application.rb:88:in `load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:72:in `block in run'
/usr/lib/ruby/vendor_ruby/rake/application.rb:160:in `standard_exception_handling'
/usr/lib/ruby/vendor_ruby/rake/application.rb:70:in `run'
/usr/bin/rake:27:in `<main>'

How do I get the rake command to work properly? I'm using Terminal in Ubuntu 14.04, with Ruby 1.9.3, RubyGems 1,8.23, and Rspec 3.0.0. Thanks in advance.

Answer 1

hope this help.

gem install rspec -v 2.9.0

It happen because:

Could not find rspec (~> 2)

while rspec version installed on your machine is: rspec-3.0.0

Source: RubyGems

Answer 2

I had the same problem, and sudo gem install -v '<3.0.0' rspec did work, but only after I uninstalled the newer version with gem uninstall rspec.

Without that uninstall first, only the later version remains active and the problem will continue.