Gem install rails - FAILS

Rails
1

Very new to Ruby/Rails, followed the download/install instructions,
until
this step:

gem install 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

/usr/local/lib/site_ruby/1.9.1/rubygems/custom_require.rb:36:in
require': cannot load such file -- mkmf (LoadError) from /usr/local/lib/site_ruby/1.9.1/rubygems/custom_require.rb:36:inrequire’
from extconf.rb:1:in `’

Gem files will remain installed in
/usr/lib/ruby/gems/1.9.1/gems/json-1.7.6
for inspection.
Results logged to
/usr/lib/ruby/gems/1.9.1/gems/json-1.7.6/ext/json/ext/generator/gem_make.out

2

On Wed, Jan 2, 2013 at 4:06 PM, Doug R. [email protected]
wrote:

/usr/local/lib/site_ruby/1.9.1/rubygems/custom_require.rb:36:in require': cannot load such file -- mkmf (LoadError) from /usr/local/lib/site_ruby/1.9.1/rubygems/custom_require.rb:36:in require’
from extconf.rb:1:in `’

Gem files will remain installed in /usr/lib/ruby/gems/1.9.1/gems/json-1.7.6
for inspection.
Results logged to
/usr/lib/ruby/gems/1.9.1/gems/json-1.7.6/ext/json/ext/generator/gem_make.out

Based on your paths I’m going to assume you are on debian-ruby so
install ruby1.9.1-dev then try again.