Ruby error when trying to install mysql2 ruby gem

I am getting the error message: installing mysql2 (0.2.7) with native extensions
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.  when the mysql2 gem is being built during a "bundle install".  I appear to be missing a library or a header for the compilation.  Can someone tell me how to fix this problem?


Using launchy (0.4.0)
Using linecache (0.43)
Using mongrel (1.1.5)
Installing mysql2 (0.2.7) with native extensions
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

C:/Ruby187/bin/ruby.exe extconf.rb
checking for rb_thread_blocking_region()... no
checking for main() in -llibmysql... no
*** 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:/Ruby187/bin/ruby
--with-mysql-dir
--without-mysql-dir
--with-mysql-include
--without-mysql-include=${mysql-dir}/include
--with-mysql-lib
--without-mysql-lib=${mysql-dir}/lib
--with-libmysqllib
--without-libmysqllib


Gem files will remain installed in C:/Ruby187/lib/ruby/gems/1.8/gems/mysql2-0.2.7 for inspection.
Results logged to C:/Ruby187/lib/ruby/gems/1.8/gems/mysql2-0.2.7/ext/mysql2/gem_make.out
An error occured while installing mysql2 (0.2.7), and Bundler cannot continue.
Make sure that `gem install mysql2 -v '0.2.7'` succeeds before bundling.