Matthias Schmidt – Bloggertastic

Since Xcode 4.2 Apple doesn’t ship a normal GCC anymore, but instead packages LLVM. While it was possible to compile Ruby with LLVM before, the result was error prone. Not anymore! Since 1.9.3-p125 Ruby is fully compatible with LLVM and here is how you can install it without the need of any additional GCC installation.

I’m going to use rbenv and ruby-build in the progress. This way everything is installed in ~/.rbenv and you won’t need any administrator privileges.

1. Install Xcode 4.3 or the new stand-alone command line tools
2. Install rbenv and ruby-build

   # install rbenv
   $ git clone git://github.com/sstephenson/rbenv.git ~/.rbenv
   $ echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> .bash_profile
   $ echo 'eval "$(rbenv init -)"' >> .bash_profile
   # You may be using Zsh or any other shell.
   # I presume you know how to adopt the previous two lines then.
   
   # install ruby-build
   $ mkdir -p ~/.rbenv/plugins
   $ git clone git://github.com/sstephenson/ruby-build.git ~/.rbenv/plugins/ruby-build
   
   # reload bash (alternatively close and re-open Terminal)
   $ source ~/.bash_profile
   

3. Compile Ruby 1.9.3-p125 and make default ruby

   $ env CC=/usr/bin/gcc rbenv install 1.9.3-p125
   $ rbenv global 1.9.3-p125
   $ rbenv rehash
   

4. Done. Check everything is ok now

   $ ruby -v
   # => ruby 1.9.3p125 (2012-02-16 revision 34643) [x86_64-darwin11.3.0]
   

Sweet. Leave a note in the comments if this helped you. Happy coding!