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 only used (where username is your Mac login username)

sudo chown -R username ~/Library/Caches/CocoaPods

and

sudo chown -R username ~/.cocoapods

when I tried with the groupname parameter I got

chown: username.groupname: illegal user name

Of course I used my own username and groupname :)