def create_repo(
    working_branch: str,
    repo_name: str,
    repo_url: str,
)
  # repo_name = myorganisation/my-repo
  # repo_url turns repo_name into a GitHub SSH URL
  # working_branch is what it sounds like. Note that the default branch for my organisation is named "main"
  
  subprocess.run(args=["gh", "repo", "create", repo_name, "--private"]) # ensure the remote exists by creating it in GitHub, therefore I expect the "main" branch to exist in the refs
  subprocess.run(args=["git", "init"])
  repo = git.Repo(str(repo_path))

  remote_name = "origin"
  remote = repo.create_remote(remote_name, repo_url)
  # maybe the remote doesn't exist?

  remote.fetch() # attempt to fetch from the remote in case that's needed to update refs

  print(os.listdir()) # indeed, there are files present besides the .git folder
  repo.head.reference = repo.create_head(working_branch) # raises the error mentioned

  remote_ref = git.RemoteReference(
      repo=repo,
      path=f"refs/remotes/{remote_name}/{working_branch}",
  )
  repo.head.reference.set_tracking_branch(remote_ref)
  branch_obj: git.Head = [h for h in repo.heads if h.name == working_branch][0] # this is old code to try and fetch refs, but none exist
  branch_obj.checkout()

  repo.index.add(["."])
  repo.index.commit("My commit")
  remote.push(set_upstream=True, kill_after_timeout=True)