Have you ever had a PR that you can’t quite merge because it needs changes, but the user has gone away (either deleted their account/branch/fork or are no longer a collaborator on a project)? Do you see “unknown repository” when you pull up the PR on GitHub?
Fear no more — you can salvage that code! Add the following line to the origin block (or whatever remote you are using — be sure to change to refs/remotes/REMOTE/pr/*) in /.git/config.
fetch = +refs/pull//head:refs/remotes/origin/pr/
Then you can do git checkout pr/### to grab their code, then git checkout -b my-new-branch to create a local branch out of the once-lost PR!
Pretty neat, eh?