Tengo la versión de Ruby ruby 1.9.2p0 (2010-08-18) [i386-mingw32] instalada en Windows7. y la gema vesion 1.3.7

Cuando intenté instalar mysql gem, se muestraFailed to build gem native extension error, ¿por qué es esto? mi versión de mysql es 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>