Green_Shoes fails to build native gem extension - ruby

Question

I'm trying to install green_shoes on Windows 8.1. I have ruby 2.0.0p451 and gem version 2.0.14 on a 64-bit OS. I also installed the ruby-gtk2 package recommended on the green_shoes page. Any idea what's up?
C:\>gem install green_shoes
Temporarily enhancing PATH to include DevKit...
Building native extensions. This could take a while...
ERROR: Error installing green_shoes:
ERROR: Failed to build gem native extension.
C:/Ruby200-x64/bin/ruby.exe extconf.rb
checking for --enable-debug-build option... no
checking for -Wall option to compiler... *** 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:/Ruby200-x64/bin/ruby
--enable-debug-build
--disable-debug-build
C:/Ruby200-x64/lib/ruby/2.0.0/mkmf.rb:434:in `try_do': The compiler failed to ge
nerate an executable file. (RuntimeError)
You have to install development tools first.
from C:/Ruby200-x64/lib/ruby/2.0.0/mkmf.rb:549:in `block in try_compile'
from C:/Ruby200-x64/lib/ruby/2.0.0/mkmf.rb:502:in `with_werror'
from C:/Ruby200-x64/lib/ruby/2.0.0/mkmf.rb:549:in `try_compile'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/glib2-2.2.3/lib/mkmf-gnome2
.rb:58:in `block in try_compiler_option'
from C:/Ruby200-x64/lib/ruby/2.0.0/mkmf.rb:895:in `block in checking_for
'
from C:/Ruby200-x64/lib/ruby/2.0.0/mkmf.rb:340:in `block (2 levels) in p
ostpone'
from C:/Ruby200-x64/lib/ruby/2.0.0/mkmf.rb:310:in `open'
from C:/Ruby200-x64/lib/ruby/2.0.0/mkmf.rb:340:in `block in postpone'
from C:/Ruby200-x64/lib/ruby/2.0.0/mkmf.rb:310:in `open'
from C:/Ruby200-x64/lib/ruby/2.0.0/mkmf.rb:336:in `postpone'
from C:/Ruby200-x64/lib/ruby/2.0.0/mkmf.rb:894:in `checking_for'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/glib2-2.2.3/lib/mkmf-gnome2
.rb:57:in `try_compiler_option'
from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/glib2-2.2.3/lib/mkmf-gnome2
.rb:67:in `<top (required)>'
from C:/Ruby200-x64/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:5
5:in `require'
from C:/Ruby200-x64/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:5
5:in `require'
from extconf.rb:15:in `<main>'
Gem files will remain installed in C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/glib2
-2.2.3 for inspection.
Results logged to C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/glib2-2.2.3/ext/glib2/
gem_make.out