Hi everyone 
This topic is meant to be as a reference for anyone debugging why their Pods caching broke and they still have AFNetworking in their Podfile.
On January 17th AFNetworking was deprecated and it's already existing podspec file has been updated accordingly.
This affects the AFNetowrking line in SPEC CHECKSUM section in the Podfile.lock
On our local machines on which pod repo update rarely runs, the old podspec and old checksum were generated and tracked on git.
While on CircleCI, which always has the latest specs repo sees the podspec and generated a new checksum post installation, which modifies the Podfile.lock on CI, which is used to generate the key for the Pods cache.
Leading to CircleCI always missing the cache because the Podfile.lock tracked in git, never producing the same key used for the Pods cache.