[joantune]

Here is the confirmation of such a mechanism (they simply rate limit certain repos):

"All of these factors combine to make CocoaPods/Specs one of the top five most resource-costly repositories that we host on all of GitHub.com. And that is why it is rate-limited; otherwise it would consume even more resources and cause service interruptions for other GitHub users. The symptoms of the rate limiting for you and your users are that your repository accesses (clones, fetches, pushes) have to wait in a queue on our end, sometimes for a long time, before being processed. This causes fetches/clones to take much longer than they would otherwise, and might cause timeouts at your end. Moreover, if the load on our servers becomes too overwhelming, a fraction of the accesses might be rejected altogether."

From: https://github.com/CocoaPods/CocoaPods/issues/4989#issuecomm...