Can't get to work CocoaPods and Yosemite - ruby

Question

I already tried this steps:
Open Xcode 6 Open Preferences
Click the Locations tab
Change the Command Line Tools version to Xcode 6.0
Uninstall cocoapods
a. $sudo gem uninstall cocoapods Install xcodeproj
a. $ sudo gem install
xcodeproj Install cocoapods
a. $ sudo gem install cocoapods
Run pod --version to verify that it worked
But I'm still gettings this when I do pod install or pod --version:
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require': cannot load such file -- xcodeproj/prebuilt/universal.x86_64-darwin14-2.0.0/xcodeproj_ext (LoadError)
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Library/Ruby/Gems/2.0.0/gems/xcodeproj-0.17.0/lib/xcodeproj/ext.rb:6:in `rescue in <top (required)>'
from /Library/Ruby/Gems/2.0.0/gems/xcodeproj-0.17.0/lib/xcodeproj/ext.rb:3:in `<top (required)>'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Library/Ruby/Gems/2.0.0/gems/xcodeproj-0.17.0/lib/xcodeproj.rb:30:in `<top (required)>'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Library/Ruby/Gems/2.0.0/gems/cocoapods-0.33.1/lib/cocoapods.rb:2:in `<top (required)>'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Library/Ruby/Gems/2.0.0/gems/cocoapods-0.33.1/bin/pod:32:in `<top (required)>'
from /usr/bin/pod:23:in `load'
from /usr/bin/pod:23:in `<main>'

Answer 1

In case someone else got the same issue, I did this to fix my issue:
Update Gems
sudo gem update --system
Uninstalled xcodeproj
sudo gem uninstall xcodeproj
Make sure to select All versions
Uninstalled Cocoapods
sudo gem uninstall cocoapods
Install xcodeproj
sudo gem install xcodeproj
Install cocoapods
sudo gem install cocoapods
Run
pod --version to test.

Answer 2

Running these 2 lines will resolve your problem
sudo gem update --system
sudo gem install cocoapods

Answer 3

I had to uninstall the entire dependency chain for cocoapods to get it to work.
for i in `gem list --no-versions`; do gem uninstall -aIx $i; done
see Uninstall all installed gems, in OSX?

Answer 4

Many of this issues are because of system-wide ruby installation and it forces developers to use "sudo" all the time (well, how many times we did "sudo gem install cocoapods --pre"). I recently had the same issue trying to install a pre-released version of cocoapods (permissions were messed up). So here is a approached that worked for me.
$ sudo gem uninstall xcodeproj
$ sudo gem uninstall cocoapods
# Let's restore Apple's ruby installation, the following is for Yosemite that has 2.0 ruby by default
$ cd /System/Library/Frameworks/Ruby.framework/Versions
$ sudo rm Current
$ sudo ln -s 2.0 Current
$ brew install ruby
(closing and opening terminal window sometimes help)
$ which ruby
should display /usr/local/bin/ruby
(should point to "local" directory now, not to "/usr/bin", if this is not the case for you, make sure to modify path order)
Now you should be able to install xcodeproj and cocoapods without using "sudo":
$ gem install xcodeproj --pre
$ gem install cocoapods --pre
(I'm using pre-released version, just remove --pre if you want to use releases instead).
Enjoy :)

Answer 5

The error 'require': cannot load such file indicates that you some missing or broken gem package. You can probably fix it by re-installing cocoapods:
gem uninstall cocoapods # Follow by sudo if necessary
gem install cocoapods --verbose # Follow by sudo if necessary
And make sure that your xcodeproj is present:
gem install xcodeproj --verbose # Follow by sudo if necessary
If won't help, try to install it by using older Ruby:
sudo ln -s /Library/Ruby/Gems/1.8/gems/rubygems-update-1.8.12/bin/gem /usr/bin/gem18
sudo gem18 install cocoapods
See:
Managing Rails Versions and Gems

Answer 6

You just have to execute this commande before :
sudo gem install cocoapods
This will update all outdated gems