rake aborted! uninitialized constant Mysql2

Goksel-Eryigits-Mac-mini:blog geryit$ rake db:migrate --trace
(in /Users/geryit/Sites/blog)
** Invoke db:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute db:migrate
rake aborted!
Client does not support authentication protocol requested by server; consider upgrading MySQL client
/Users/geryit/.rvm/rubies/ruby-1.8.7-p330/lib/ruby/1.8/mysql.rb:453:in `read'
/Users/geryit/.rvm/rubies/ruby-1.8.7-p330/lib/ruby/1.8/mysql.rb:130:in `real_connec开发者_开发技巧t'
/Users/geryit/.rvm/gems/ruby-1.8.7-p330/gems/activerecord-3.0.3/lib/active_record/connection_adapters/mysql_adapter.rb:600:in `connect'
/Users/geryit/.rvm/gems/ruby-1.8.7-p330/gems/activerecord-3.0.3/lib/active_record/connection_adapters/mysql_adapter.rb:164:in `initialize
.
.
.

database.yml

development:
  adapter: mysql
  encoding: utf8
  database: test
  pool: 5
  username: root
  password:
  socket: /tmp/mysql.sock

Have you defined

gem 'mysql2'

in Gemfile? For Rails 3 and Bundler, it's not enough to install the gem, but to include it in Gemfile.

They work together now without any problems. The problem was Mysql version and mysql gem flags. I removed MYSQL 5.5 and installed Mysql 5.1 back. Everything is fixed. Thanks.

I wrote a blog post about installing, it can be helpful : https://geryit.com/blog/installing-mysql-with-rails-on-mac-os-x-snow-leopard/

Try uninstalling the mysql gem. It might be conflicting with the mysql2 gem you're using in your database.yml.

I was getting 'uninitialized constant Mysql' on Snow Leopard and Rails 3. Adding 'mysql' gem to Gemfile fixed it for me.