% git pull The authenticity of host 'git.gnu.org (140.186.70.72)' can't be established. RSA key fingerprint is 80:5a:b0:0c:ec:93:66:29:49:7e:04:2b:fd:ba:2c:d5. Are you sure you want to continue connecting (yes/no)? yes Failed to add the host to the list of known hosts (/Users/lhc/.ssh/known_hosts). Permission denied (publickey). fatal: The remote end hung up unexpectedly
The file, /Users/lhc/.ssh/known_hosts, has to be writable. As pointed out by the error message. Why that isn't the case, I don't know; check that you own the file and that it is writable.
