• [!] Unable to satisfy the following requirements: ......

Solution:

$ sudo rm -fr ~/.cocoapods/repos/master
$ pod setup

Ref: http://blog.cocoapods.org/Repairing-Our-Broken-Specs-Repository/

• [!] /usr/local/bin/git remote update error: cannot open FETCH_HEAD: Permission denied.....

Solution:

$ sudo chown -R username:groupname ~/Library/Caches/CocoaPods
$ sudo chown -R username:groupname ~/.cocoapods

Note: Replace username and groupname with your Mac login username/groupname. If you don't have groupname, just enter username.

Ref: http://stackoverflow.com/questions/16049335/cocoapods-pod-install-permission-denied