Error:failed to build gem native extension

The Ruby on Rails Web site says that running gem install rails after installing Ruby is good.

But the whole process took me a couple of hours. First of all, OpenSUSE 13.1 comes with Ruby 2.0.0p-247, and I offload Ruby because I intend to use rbenv to manage Ruby:

$ sudo zypper rm Ruby

As a result, Konsole is gone, YAST is gone, and it seems that the KDE desktop has been unloaded.

Then you will have to use the system itself. But the gem install rails has an error:

Building native extensions. This is could take a while ...

Error:error Installing rails:

Error:failed to build gem native extension.

/usr/bin/ruby2.0 extconf.rb

MKMF.RB can ' t find header files for Ruby At/usr/lib/ruby/include/ruby.h

Gem files would remain installed in/usr/lib/ruby/gems/2.0.0/gems/atomic-1.1.14 for inspection.

Results logged To/usr/lib/ruby/gems/2.0.0/gems/atomic-1.1.14/ext/gem_make.out

Gem install compass is no problem.

The information on the net says to install Ruby-devel:

sudo zypper in Ruby-devel

Install Rails again, as you can see, from the time I started writing this to now, it's still in the installation. But then it was finally installed.