git@github.com: Permission denied (publickey)

If you ever receive this message when attempting to clone a git repository try the following.

# Should return: Agent pid [process pid]
eval "$(ssh-agent -s)"

# Should return Identity Added: ...
ssh-add ~/.ssh/id_rsa ( Run ssh-keygen to generate a key if you haven't already )

# Add your ~/.ssh/id_rsa.pub file to your GitHub keys if it's not already there

This article assumes you are running a Unix-based system like Linux or macOS.