CocoaPods: pod update/install stuck at “Pre-downloading …”

CocoaPods is a dependency manager for Swift and Objective-C Cocoa projects.

When CocoaPods stops the execution of install or update command, it’s helpful to clean the CocoaPod cache using the following commands:

rm -rf "${HOME}/Library/Caches/CocoaPods" 
rm -rf "`pwd`/Pods/" 

After this, the update (or install) should run smoothly:

pod update