So I upgraded to OSX Mavericks and I wanted to write on my blog. So I go to install jekyll:

$ sudo gem install jekyll

And I get this error:

ERROR:  Error installing jekyll:
ERROR: Failed to build gem native extension.

/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rb
mkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/include/ruby.h

So here’s how I fixed it:

1. Make sure you have xcode developer

Run the following in terminal to install Xcode Command Line Tools on Mac OSX 10.9 Mavericks

$ xcode-select --install

When a popup shows, click Install

2. Get Ruby and Ruby Gems

Run the following in terminal to get the most updated versions of Ruby and RubyGems

$ \curl -L https://get.rvm.io | bash -s stable --ruby

3. Install Jekyll

Now you can install jekyll with the following command:

$ sudo gem install jekyll

4. Serve up your site

Then run this in terminal and then visit http://localhost:4000/

$ jekyll serve --watch

And in case you forgot, here are the Basics for Jekyll.

Enjoy.