can't activate test-unit (= 1.2.3), already activated test-unit-2.3.0

Recently I added rspec test in my rails 2.3.5 but I wasn't able to run simply rake -T command. Then I found Rails 3 - If I'm using RSpec, can I just del开发者_高级运维ete the 'test' folder? and I added gem test-unit in my Gemfile. This is showing me below message.

rake aborted!
can't activate test-unit (= 1.2.3), already activated test-unit-2.3.0. Make sure all dependencies are added to Gemfile.

You are trying to load old version of test-unit where new version is already activated. To fix this bug do either one

1.Removing your new version of test-unit

2.Find test-unit 1.2.3 version in rake file and replace it with 2.3.0

You must to doing something like config.gem 'test-unit', :version => '1.2.3' somewhere in test.rb. Remove this line and see if that works.

Try running

bundle exec rake -T

That will run the rake command in the context of your bundle which should lock in the correct version of all of your gems.