cocoaPods pod install Permission denied

Question

This is the short version:

When I run

pod install 

in an Xcode project I get

[!] Pod::Executable pull erro

Answer 1

I solved it by installing the most up to date version of Ruby. Instructions here: https://gorails.com/setup/osx/10.12-sierra I was then able to successfully run sudo gem update sudo gem install cocoapods