You really just need a TCP pathway between your CI and some machine with the git repo on it.
Or take your local copy and use git-fu commands to create a bare repo of it that you can compress and put somewhere like S3. Then download it in CI and checkout from that.
Or just tarball your app source, who cares about git, and do the same (s3, give it a direct path to the asset)
All of this is potentialy useless info though. Hard to say without understanding how your CI works. If all you need is the source code, there are a half dozen ways to get that source into CI without git.
Or take your local copy and use git-fu commands to create a bare repo of it that you can compress and put somewhere like S3. Then download it in CI and checkout from that.
Or just tarball your app source, who cares about git, and do the same (s3, give it a direct path to the asset)
All of this is potentialy useless info though. Hard to say without understanding how your CI works. If all you need is the source code, there are a half dozen ways to get that source into CI without git.