Error installing mysql2: Failed to build gem native extension

Question

I am having some problems when trying to install mysql2 gem for Rails. When I try to install it by running bundle install or gem install mysq

Answer 1

For windows user: You set the lib and include path of your mysql, for instance, if youre using xampp you can have like this:

gem install mysql2 -- '--with-mysql-lib="C:\xampp\mysql\lib" --withmysql-include="C:\xampp\mysql\include"'

Answer 2

here is a solution for the windows users, hope it helps!

Using MySQL with Rails 3 on Windows

• Install railsinstaller -> www.railsinstaller.org (I installed it to c:\Rails)

• Install MySQL (I used MySQL 5.5) -> dev.mysql.com/downloads/installer/

--- for mySQL installation ---

If you dont already have these two files installed you might need them to get your MySQL going

vcredist_x86.exe -> http://www.microsoft.com/download/en/details.aspx?id=5555 dotNetFx40_Full_x86_x64.exe -> http://www.microsoft.com/download/en/details.aspx?id=17718

Use default install Developer Machine

-MySQL Server Config-
port: 3306
windows service name: MySQL55
mysql root pass: root (you can change this later)
(username: root)
-MySQL Server Config-

--- for mySQL installation ---

--- Install the mysql2 Gem ---

Important: Do this with Git Bash Command Line(this was installed with railsinstaller) -> start/Git Bash

gem install mysql2 -- '--with-mysql-lib="c:\Program Files\MySQL\MySQL Server 5.5\lib" --with-mysql-include="c:\Program Files\MySQL\MySQL Server 5.5\include"'

Now the gem should have installed correctly

Lastly copy the libmysql.dll file from
C:\Program Files\MySQL\MySQL Server 5.5\lib
to
C:\Rails\Ruby1.9.2\bin

--- Install the mysql2 Gem ---

You will now be able to use your Rails app with MySQL, if you are not sure how to create a Rails 3 app with MySQL read on...

---

--- Get a Rails 3 app going with MySQL ---

Open command prompt(not Git Bash) -> start/cmd
Navigate to your folder (c:\Sites)
Create new rails app

rails new world

Delete the file c:\Sites\world\public\index.html
Edit the file c:\Sites\world\config\routes.rb
add this line -> root :to => 'cities#index'

Open command prompt (generate views and controllers)

rails generate scaffold city ID:integer Name:string CountryCode:string District:string Population:integer

Edit the file c:\Sites\world\app\models\city.rb to look like this

class City < ActiveRecord::Base
 set_table_name "city"
end

Edit the file c:\Sites\world\config\database.yml to look like this

development:
adapter: mysql2
encoding: utf8
database: world
pool: 5
username: root
password: root
socket: /tmp/mysql.sock

add to gemfile

gem 'mysql2'

Open command prompt windows cmd, not Git Bash(run your app!)
Navigate to your app folder (c:\Sites\world)

rails s

Open your browser here -> http://localhost:3000

--- Get a Rails 3 app going with MySQL ---

Answer 3

After you get the mysql-dev issues corrected, you may need to remove the bad mysql2 install. Look carefully at the messages after $ bundle install. You may need to

rm -rf vendor/cache/
rm -rf ./Zentest

This will clear out the bad mysql2 installation so that a final $ bundle install can create a good one.