Trying to install ruby-debug on RubyStack 3.2.3

TryingToInstallRubyDebugOnRubyStack3-2-4.txt

C:\RubyStack-3.2.3-0>gem install ruby-debug
Temporarily enhancing PATH to include DevKit...
Building native extensions.  This could take a while...
ERROR:  Error installing ruby-debug:
        ERROR: Failed to build gem native extension.

        C:/RubyStack-3.2.3-0/ruby/bin/ruby.exe extconf.rb
Can't handle 1.9.x yet
*** 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:/RubyStack-3.2.3-0/ruby/bin/ruby


Gem files will remain installed in C:/RubyStack-3.2.3-0/ruby/lib/ruby/gems/1.9.1
/gems/linecache-0.46 for inspection.
Results logged to C:/RubyStack-3.2.3-0/ruby/lib/ruby/gems/1.9.1/gems/linecache-0
.46/ext/gem_make.out