Install Rails Failed on OSX 10.8.4

Install Rails Failed on OSX 10.8.4

I always failed to install rails on my new Air with OSX 10.8.4, even I
succeed installed ruby2, Command Line Tool of XCode, it still prompts some
error when I try to install rails.
I found lots solutions from the Internet, but they all don't work on my
issue, I'm completely confused, doesn't any can help me? I'll really
appreciate!!!



localhost:myapp zerocool$ ruby -v
ruby 2.0.0p247 (2013-06-27 revision 41674) [x86_64-darwin12.3.0]
localhost:myapp zerocool$ sudo gem install rails Password: Building native
extensions. This could take a while... ERROR: Error installing rails:
ERROR: Failed to build gem native extension.
/Users/zerocool/.rvm/rubies/ruby-2.0.0-p247/bin/ruby extconf.rb
* 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=/Users/zerocool/.rvm/rubies/ruby-2.0.0-p247/bin/ruby
--with-atomic_reference-dir --without-atomic_reference-dir
--with-atomic_reference-include
--without-atomic_reference-include=${atomic_reference-dir}/include
--with-atomic_reference-lib
--without-atomic_reference-lib=${atomic_reference-dir}/
/Users/zerocool/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/mkmf.rb:434:in
try_do': The compiler failed to generate an executable file.
(RuntimeError) You have to install development tools first. from
/Users/zerocool/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/mkmf.rb:519:intry_link0'
from
/Users/zerocool/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/mkmf.rb:817:in
try_run' from extconf.rb:24:in'
Gem files will remain installed in
/Users/zerocool/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/atomic-1.1.12
for inspection. Results logged to
/Users/zerocool/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/atomic-1.1.12/ext/gem_make.out