Running CocoaPods on “old” versions of OS X / macOS might lead to some weird behaviour – namely CocoaPods telling you that GitHub might be down:
$ pod repo update --verbose
Updating spec repo `master`
[!] Failed to connect to GitHub to update the CocoaPods/Specs specs repo - Please check if you are offline, or that GitHub is down
/Library/Ruby/Gems/2.0.0/gems/cocoapods-core-1.3.1/lib/cocoapods-core/github.rb:105:in `rescue in modified_since_commit'
[...]
The error message does not only sound insane, it is actually completely misleading. The issue seems to be caused by a failing request to GitHub. Originating from a failed TLS handshake (as it happens quite often with the older Ruby 2.0.0 version). More recent versions of Ruby don’t have a problem with communicating via SSL. Using a more recent Ruby version does in fact circumvent the issue:
brew install ruby
sudo gem install cocoapods
Depending on your system, you might need to forcefully “overwrite” the Ruby installation using brew link:
brew link --overwrite ruby