Received disconnect from port 22:2: too many authentication failures というエラーが出たので対応した.
$ git fetch -p
> Received disconnect from port 22:2: too many authentication failures
> Authentication failed.
> fatal: Could not read from remote repository.
>
> Please make sure you have the correct access rights
> and the repository exists.
$ vi ~/.ssh/config
Host bitbucket.org
AddKeysToAgent no
IdentitiesOnly yes
HostName bitbucket.org
IdentityFile /PATH/TO/.ssh/id_rsa
$ chmod 600 ~/.ssh/config