Error while rake db:migrate

" You have already activated rake 0.9.0, but your Gemfile requires rake 0.8.7 "

Solved it:

You'll need to tell bundle to update the rake version it's using for your app  bundle update rake It'll update your Gemfile.lock for you. Other solution : http://stackoverflow.com/questions/6080040/you-have-already-activated-rake-0-9-0-but-your-gemfile-requires-rake-0-8-7