Cocoapods error reading ~/.cocoapods/repos/master/CocoaPods-version.yml after reinstall

Ok, found the same problem thread on github. Answered by csknns.

Here is how it went for me, re-install psych:

$ sudo gem uninstall psych
Password:

Select gem to uninstall:
 1. psych-2.0.5
 2. psych-2.0.6
 3. psych-2.0.8
 4. All versions
> 4
Successfully uninstalled psych-2.0.5
Successfully uninstalled psych-2.0.6
Successfully uninstalled psych-2.0.8

$ sudo gem install psych -v 2.0.0
Fetching: psych-2.0.0.gem (100%)
Building native extensions.  This could take a while...
Successfully installed psych-2.0.0
Parsing documentation for psych-2.0.0
Installing ri documentation for psych-2.0.0
Done installing documentation for psych after 2 seconds
1 gem installed

$ pod setup
Setting up CocoaPods master repo
Already up-to-date.
Setup completed

Hope this helps someone out there!

This bug seems to be fixed in newer versions of RubyGems. Updating with gem update --system allows me to update to the latest version of psych without breaking CocoaPods.

Credit: https://github.com/CocoaPods/CocoaPods/issues/3539#issuecomment-125106504