Cocoapods: LoadError - no such file to load

I also was seeing this. Running this fixed the issue:

sudo gem install cocoapods && pod install

Finally found a solution: I'm running old Xcode4 and new Xcode5 in same machine with same projects. At some point I seem to have lost command line tools (and iPhone5 simulator).

Reinstalling command line tools solved the problem for me. Since Xcode 4.6.3 menu item Xcode - Preferences - Downloads - Components didn't have command-line tools any more for unknown reasons, here is another way to install them:

xcode-select --install--install          Opens a user interface dialog to request automatic installation of the          command line developer tools.

Now running "pod install" worked just fine.

if you are using 10.10 and are seeing this error (/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:) try this

Open Xcode 6 > Preferences > LocationsCommand Line Tools version to Xcode 6.0Uninstall cocoapods/xcodeproj then re-install.sudo gem uninstall cocoapodssudo gem uninstall xcodeprojsudo gem install xcodeprojsudo gem install cocoapodspod --version