I had the need to have 2 GitHub repositories with the same exact content.
Whenever I pushed my changes, those changes had to be sent to those 2 repositories without any extra work.
So here’s what I did.
I already had a working repository with some code, set up as the
origin remote in Git.
I created a new empty repository on GitHub, and I set is as another URL for the
git remote set-url --add --push origin firstname.lastname@example.org:flaviocopes/original.git
git remote set-url --add --push origin email@example.com:flaviocopes/clone.git
That’s it. Now doing a “git push” sends the changes to both repositories.