Ruby gem mysql2 install error - ruby

Question

I have the Ruby version ruby 1.9.2p0 (2010-08-18) [i386-mingw32] installed in Windows7.
and the gem vesion 1.3.7
When i tried to install mysql gem, it is showing Failed to build gem native extension error, why is this? my mysql version is 5.1.36(WampServer)
E:\RubyApps\test_app2>gem install mysql2
Building native extensions. This could take a while...
ERROR: Error installing mysql2:
ERROR: Failed to build gem native extension.
E:/Ruby192/bin/ruby.exe extconf.rb
checking for rb_thread_blocking_region()... *** 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=E:/Ruby192/bin/ruby
E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:368:in `try_do': The complier failed to genera
te an executable file. (RuntimeError)
You have to install development tools first.
from E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:435:in `try_link0'
from E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:440:in `try_link'
from E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:552:in `try_func'
from E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:797:in `block in have_func'
from E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:693:in `block in checking_for'
from E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:280:in `block (2 levels) in postp
one'
from E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:280:in `block in postpone'
from E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:276:in `postpone'
from E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:692:in `checking_for'
from E:/Ruby192/lib/ruby/1.9.1/mkmf.rb:796:in `have_func'
from extconf.rb:9:in `<main>'
Gem files will remain installed in E:/Ruby192/lib/ruby/gems/1.9.1/gems/mysql2-0.
2.3 for inspection.
Results logged to E:/Ruby192/lib/ruby/gems/1.9.1/gems/mysql2-0.2.3/ext/mysql2/ge
m_make.out
E:\RubyApps\test_app2>

Answer 1

If you are having this same problem in Linux, basically you just need to install a few libraries first. This worked for me.
> sudo apt-get install libmysql-ruby libmysqlclient-dev
> gem install mysql
source: http://heatware.net/ruby-rails/solved-installing-mysql-gem-extconf-rb-failed-error/

Answer 2

Since this keeps coming up on google as on of the top results, I should point out that this answers is from almost 2 years ago. Here is a more updated answer: How to use "mysql2" gem in Rails 3 application on Windows 7?
According to the developer there is a already a reported bug for it and he is working on parting mysql2 over to Windows. As of now - it's still in the works. Use the older mysql driver for now - or use sqlite for local development.
This is from the googlegroups discussion
Blockquote
Hey Erwann,
There's a ticket on the mysql2 issue tracker for Win32 support already
at http://github.com/brianmario/mysql2/issues#issue/8 . You can follow
it for progress; I'm doing my best to get things working smoothly for
you guys. Hang tight! :)

Answer 3

Just for the record: The problem should be solved!
The mysql2 gem v.0.2.6 is out, having win32 support.
gem install mysql2 worked without problems now.
See: http://github.com/brianmario/mysql2/issues/issue/8#issue/8/comment/479748

Answer 4

it works,
c:> gem install mysql2 -- '--with-mysql-lib="C:\Prog
ram Files\MySQL\MySQL Connector C 6.0.2\lib\opt" --with-mysql-include="C:\Progra
m Files\MySQL\MySQL Connector C 6.0.2\include"'
Temporarily enhancing PATH to include DevKit...
Building native extensions. This could take a while...
Successfully installed mysql2-0.3.6
1 gem installed
Installing ri documentation for mysql2-0.3.6...
Enclosing class/module 'mMysql2' for class Client not known
Installing RDoc documentation for mysql2-0.3.6...
Enclosing class/module 'mMysql2' for class Client not known
Note:
I. If there is no lib and include directory in your mysql then install mysql connector c
II. First install DevKit then only you can install mysql2 plugin in windows
https://github.com/oneclick/rubyinstaller/wiki/Development-Kit

Answer 5

You can try
gem install mysql2 -v '0.0.00' -- --with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include

Answer 6

Have you installed the DevKit correctly? If doubt, cross check the steps of installation on -
http://rorguide.blogspot.com/2011/03/installing-mysql2-gem-on-ruby-192-and.html
I was able to install mysql2 gem after following these steps.

Answer 7

Under Cygwin, I had to be sure to install not just libmysqlclient18, but also libmysqlclient-devel. Then "gem install mysql2" went fine.
There is also, of course, a ruby-mysql2 package in Cygwin.

Answer 8

key: the line that says You have to install development tools first.
ref: devkit

Answer 9

use
gem install mysql
for windows, till mysql2 get it right.