Missing gem when running rake

I'm using rbenv with Ruby 1.9.2-p290, Rails 3.1, and the database is MySQL.

When I try

rake db:create

I get the following error:

Could not find multi_json-1.0.3 in any of the sources

I've also tried bundle exec rake db:create.

My GemFile looks like this:

source 'http://rubygems.org'

gem 'rails', '3.1.0'
gem 'mysql2'
gem 'json'

group :assets do
  gem 'sass-rails', "  ~> 3.1.0"
  gem 'coffee-rail开发者_StackOverflow中文版s', "~> 3.1.0"
  gem 'uglifier'
end

gem 'jquery-rails'

Quite old, but in case anyone else comes across this and is looking for the real answer: upgrade your bundler gem.

For me didn't work neither smathy and kalleth answers.

Always getting:

Could not find multi_json-1.3.0 in any of the sources

What it worked for me was deleting Gemfile.lock and running again bundle install

It installed a new version of multi_json:

Installing multi_json (1.3.2) 

I ran into this problem too with a Rails 3.1 application + rails engines . bundle exec rake -T reported the error you're reporting.

What solved it for me was running the following command to tell bundler to install the gems to the local 'vendor/bundle' path within the application with the following command:

bundle install --path=vendor/bundle

After I did that, bundle exec rake -T worked correctly.

I had the same problem, and used Jorge's answer to get to my solution:

bundle update multi_json

This just updates multi_json, and not all the other gems, which would potentially happen when you delete the Gemfile.lock and run "bundle install".

Always run your commands through bundle exec. That way you ensuer that you load the correct environment which is expected by your app. Use it like:

bundle exec rake db:migrate

Also make sure you have actually run bundle install to install all required gems and their dependencies.