Instalation help

Hi guys, my first post :smiley:

I have a problem installing rails

Building native extensions. This could take a while...
ERROR: Error installing rails:
  ERROR: Failed to build gem native extension.

        /usr/bin/ruby1.9.1 extconf.rb
extconf.rb:36:in `require': no such file to load -- mkmf (LoadError)
  from extconf.rb:36:in `<main>'

Gem files will remain installed in /usr/lib/ruby/gems/1.9.1/gems/
bcrypt-ruby-3.0.1 for inspection.
Results logged to /usr/lib/ruby/gems/1.9.1/gems/bcrypt-ruby-3.0.1/ext/
mri/gem_make.out

someone help me ..

Thank you very much

Building native extensions. This could take a while...
ERROR: Error installing rails:
ERROR: Failed to build gem native extension.

   /usr/bin/ruby1\.9\.1 extconf\.rb

extconf.rb:36:in `require': no such file to load -- mkmf (LoadError)
from extconf.rb:36:in `<main>'

For me it helped to install the source-packages of ruby and its dependencies.