Error when install pods

The following error was obtained when installing pods

/Users/mosab/.gem/ruby/1.8/gems/cocoapods-0.30.0/lib/cocoapods.rb:12: undefined method `enforce_available_locales=' for I18n:Module (NoMethodError)
from /Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `gem_original_require'
from /Library/Ruby/Site/1.8/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/mosab/.gem/ruby/1.8/gems/cocoapods-0.30.0/bin/pod:32
from /usr/bin/pod:23:in `load'
from /usr/bin/pod:23

How do you install pods?

To install the pods, do one of the following: Place the caret at the code line where you add the pod, press ⌥ ⏎ , select Install, and press ⏎ . Click Install pods in the top-left corner of the editor window. From the main menu, select Tools | CocoaPods | Install.

Try "sudo gem update i18n" in your command line. Then re-run your pod command.

This fixed it for me.