Having errors with rake db:create - ruby-on-rails

Question

I'm trying to install fat free crm with ruby on rails on Windows 7, but when I put the command
rake db:create RAILS_ENV=production
it says
rake aborted!
LoadError: cannot load such -- 2.1/pg_ext
Normally, it would say what gem I should install, but not in this case.
How can I solve this error?
Edit:
A friend of mine suggested to uncomment mysql2 and comment pg on the Gemfile file in the proyect like this:
gem 'mysql2'
#gem 'sqlite3'
#gem 'pg'
But now I get this:
Unable to load the EventMachine C extension; To use the pure-ruby reactor, requi
re 'em/pure_ruby'
C:/Ruby21/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require': ca
nnot load such file -- 2.1/rubyeventmachine (LoadError)
Have any ideas of why this happends?
Here is my Gemfile:
source 'https://rubygems.org'
# Uncomment the database that you have configured in config/database.yml
# ----------------------------------------------------------------------
gem 'mysql2'
# gem 'sqlite3'
# gem 'pg'
# Removes a gem dependency
def remove(name)
#dependencies.reject! {|d| d.name == name }
end
# Replaces an existing gem dependency (e.g. from gemspec) with an alternate source.
def gem(name, *args)
remove(name)
super
end
# Bundler no longer treats runtime dependencies as base dependencies.
# The following code restores this behaviour.
# (See https://github.com/carlhuda/bundler/issues/1041)
spec = Bundler.load_gemspec( File.expand_path("../fat_free_crm.gemspec", __FILE__) )
spec.runtime_dependencies.each do |dep|
gem dep.name, *(dep.requirement.as_list)
end
# Remove premailer auto-require
gem 'premailer', :require => false
# Remove fat_free_crm dependency, to stop it from being auto-required too early.
remove 'fat_free_crm'
group :development do
# don't load these gems in travis
unless ENV["CI"]
gem 'thin'
gem 'quiet_assets'
gem 'capistrano'
gem 'capistrano-bundler'
gem 'capistrano-rails'
gem 'capistrano-rvm'
#~ gem 'capistrano-chruby'
#~ gem 'capistrano-rbenv'
gem 'guard'
gem 'guard-rspec'
gem 'guard-rails'
gem 'rb-inotify', :require => false
gem 'rb-fsevent', :require => false
gem 'rb-fchange', :require => false
end
end
group :development, :test do
gem 'rspec-rails', '~> 2'
gem 'headless'
gem 'debugger', :platforms => 'mri_19' unless ENV["CI"]
gem 'byebug', :platforms => ['mri_20', 'mri_21'] unless ENV["CI"]
gem 'pry-rails' unless ENV["CI"]
end
group :test do
gem 'capybara'
gem 'selenium-webdriver'
gem 'database_cleaner'
gem "acts_as_fu"
gem 'factory_girl_rails'
gem 'zeus' unless ENV["CI"]
gem 'coveralls', :require => false
gem 'timecop'
end
group :heroku do
gem 'unicorn', :platform => :ruby
gem 'rails_12factor'
end
# Gems used only for assets and not required
# in production environments by default.
group :assets do
gem 'sass-rails', '~> 3.2.3'
gem 'coffee-rails', '~> 3.2.1'
gem 'uglifier', '>= 1.0.3'
gem 'execjs'
gem 'therubyracer', :platform => :ruby unless ENV["CI"]
end
gem 'turbo-sprockets-rails3'

Answer 1

It sounds like you are missing the pg gem from your Gemfile. Is it in the development group?
Can you post your Gemfile?
Uncomment #gem pg.
Unable to load the EventMachine C extension; To use the pure-ruby reactor, require 'em/pure_ruby' is a separate error. Where did you get that Gemfile?