Github で Permission denied (publickey). と言われた時

Error

$ git push -u origin master                                                                           
Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

解決策

GitHub の [ssh の設定] (https://github.com/settings/ssh) に公開 (~/.ssh/id_rsa.pub) を登録すればよい。