How do I setup an old ikiwiki repository on a new system?

I have a git repository from an old ikiwiki system.
I reformatted that hard drive, but saved the repository.

I copied it the repository to my new system, which is now the "master" host.
I installed ikiwiki on the new system.

How do I set up an ikiwiki system using a pre-existing repository (instead of creating a new one)? --[[JosephTurian]]