    # File lib/chef/knife/core/cookbook_scm_repo.rb, line 96
          def merge_updates_from(cookbook_name, version)
            branch = "chef-vendor-#{cookbook_name}"
            Dir.chdir(repo_path) do
              if system("git merge #{branch}")
                ui.info("Cookbook #{cookbook_name} version #{version} successfully installed")
              else
                ui.error("You have merge conflicts - please resolve manually")
                ui.info("Merge status (cd #{repo_path}; git status):")
                system("git status")
                exit 3
              end
            end
          end