# File lib/git-up.rb, line 222
  def rebase(target_branch)
    current_branch = repo.head
    arguments = config("rebase.arguments")

    output, err = repo.git.sh("#{Grit::Git.git_binary} rebase #{arguments} #{target_branch.name}")

    unless on_branch?(current_branch.name) and is_fast_forward?(current_branch, target_branch)
      raise GitError.new("Failed to rebase #{current_branch.name} onto #{target_branch.name}", output+err)
    end
  end