cannot install ruby-debug-base

excuse me,
I want install ruby-debug-base.. but,

# gem install -V ruby-debug-base
bla.. bla..
bla.. bla..
/usr/local/lib/ruby/gems/1.9.1/gems/linecache-0.43/test/short-file
Building native extensions. This could take a while...
ERROR: Error installing ruby-debug-base:
   ERROR: Failed to build gem native extension.

/usr/local/bin/ruby 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=/usr/local/bin/ruby

Gem files will remain installed in /usr/local/lib/ruby/gems/1.9.1/gems/
linecache-0.43 for inspection.
Results logged to /usr/local/lib/ruby/gems/1.9.1/gems/linecache-0.43/
ext/gem_make.out

what should I do?
Thanks in Advance

excuse me,
I want install ruby-debug-base.. but,

# gem install -V ruby-debug-base
bla.. bla..
bla.. bla..
/usr/local/lib/ruby/gems/1.9.1/gems/linecache-0.43/test/short-file
Building native extensions. This could take a while...
ERROR: Error installing ruby-debug-base:
ERROR: Failed to build gem native extension.

[snip]

Gem files will remain installed in /usr/local/lib/ruby/gems/1.9.1/gems/
linecache-0.43 for inspection.
Results logged to /usr/local/lib/ruby/gems/1.9.1/gems/linecache-0.43/
ext/gem_make.out

what should I do?
Thanks in Advance

ruby 1.9 requires ruby-debug19 instead of ruby-debug

Fred