Rails Server causes error with Mysql2

Question

I am running Rails 3.2 and Ruby 2.0 on a Windows 7 machine. I finally got Mysql2 installed (at least I thought so). I can run "bundle install" with no problem, and mysql2 v.0.3.16 shows up in my gem bundle.

But when I run "gem install mysql2" it fails due to native extensions. Now I am trying to run "rails s" to start my server, and I am getting more errors.

Stealth@STEALTH-PC ~/Documents/GitHub/flitti (tony-dev)
$ rails s
DL is deprecated, please use Fiddle
c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/mysql2-0.3.16/lib/mysql2.rb
:8:in `require': cannot load such file -- mysql2/mysql2 (LoadError)
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/mysql2-0.3.16/
lib/mysql2.rb:8:in `<top (required)>'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/
lib/bundler/runtime.rb:72:in `require'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/
lib/bundler/runtime.rb:72:in `block (2 levels) in require'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/
lib/bundler/runtime.rb:70:in `each'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/
lib/bundler/runtime.rb:70:in `block in require'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/
lib/bundler/runtime.rb:59:in `each'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/
lib/bundler/runtime.rb:59:in `require'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/
lib/bundler.rb:132:in `require'
        from c:/Users/Stealth/Documents/GitHub/flitti/config/application.rb:7:in
 `<top (required)>'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/railties-3.2.1
2/lib/rails/commands.rb:53:in `require'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/railties-3.2.1
2/lib/rails/commands.rb:53:in `block in <top (required)>'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/railties-3.2.1
2/lib/rails/commands.rb:50:in `tap'
        from c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/railties-3.2.1
2/lib/rails/commands.rb:50:in `<top (required)>'
        from script/rails:6:in `require'
        from script/rails:6:in `<main>'

My Gemfile looks like this

source 'https://rubygems.org'

gem 'rails', '3.2.12'
gem 'foundation-rails'
gem 'mysql2'
gem 'merit'
gem 'devise'
gem 'paperclip', '3.4.0'
gem 'pry'
gem 'mailboxer'
gem 'simple_form'
gem 'thumbs_up'
gem 'jquery-rails'

gem 'faye'
gem 'private_pub', :git => 'git://github.com/ryanb/private_pub.git'
gem 'thin'
gem 'pjax_rails'

group :assets do
  gem 'sass-rails',   '~> 3.2.3'
  gem 'coffee-rails', '~> 3.2.1'
  gem 'uglifier', '>= 1.0.3'
end


group :development, :test do
    gem 'rspec-rails'
    gem 'factory_girl_rails'
end

group :test do
    gem 'faker'
  gem "capybara"
  gem "guard-rspec"
  gem "launchy"
end

How can I fix this so I can get my rails server working?

Native Extensions Error:

Stealth@STEALTH-PC /c
$ gem install mysql2 --platform=ruby -- '--with-mysql-dir="C:\mysql-connector-c
"'
Temporarily enhancing PATH to include DevKit...
Building native extensions with: '--with-mysql-dir="C:\mysql-connector-c"'
This could take a while...
ERROR:  Error installing mysql2:
        ERROR: Failed to build gem native extension.

    c:/RailsInstaller/Ruby2.0.0/bin/ruby.exe extconf.rb --with-mysql-dir="C:\mys
ql-connector-c"
checking for ruby/thread.h... yes
checking for rb_thread_call_without_gvl() in ruby/thread.h... yes
checking for rb_thread_blocking_region()... yes
checking for rb_wait_for_single_fd()... yes
checking for rb_hash_dup()... yes
checking for rb_intern3()... yes
-----
Cannot find include dir(s) C:\mysql-connector-c/include
-----
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=c:/RailsInstaller/Ruby2.0.0/bin/ruby
        --with-mysql-dir
        --with-mysql-include
        --without-mysql-include=${mysql-dir}/include
        --with-mysql-lib
        --without-mysql-lib=${mysql-dir}/
        --with-mysql-dir
        --with-mysql-include
        --without-mysql-include=${mysql-dir}/include
        --with-mysql-lib
        --without-mysql-lib=${mysql-dir}/lib


Gem files will remain installed in c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0
.0/gems/mysql2-0.3.16 for inspection.
Results logged to c:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/mysql2-0.
3.16/ext/mysql2/gem_make.out

Answer 1

Looks like a standard mingw32 issue with mysql2

--

The problem is that since Windows does not come with MYSQL already installed, you've got to install it from scratch. It seems you're privvy to this already, but because there's a new release of mysql2 , you've got to update your C-Connector headers

We've written a tutorial on how to do this here

--

Fix

I would do this:

1. gem uninstall mysql2
2. Download the latest 32-bit version of mysql c-connector
3. Save the zip file & unpack it to a directory with no spaces
4. Once on your system, type this into cmd: gem install mysql2 —platform=ruby — '—with-mysql-dir=”C:\\mysql-connector-path”'
5. Finally, copy libmysql.dll from your mysql/bin directory to your ruby/bin directory
6. Remove the mysql c-connector files

This should install it for you so you can use it without issue

Answer 2

First do:

gem uninstall mysql2

Then do:

Bundle install

It happened when I upgraded from ubuntu 14.04 to 16.04 . I did the above 2 steps and it corrected.