anchor.diff:           list/1,
            upgrade/1,
            upgrade_project_plugin/1,
  +         upgrade_no_args/1,
            sub_app_plugins/1,
            sub_app_plugin_overrides/1,
            project_plugins/1,
  
positive.code:      ),
  
      rebar_test_utils:run_and_check(
          Config, RConf, ["plugins", "upgrade"],
          {ok, [{app, Name, valid}, {file, PluginBeam}, {plugin, PkgName}]}
       ).
  
  
negative.code:         Config, RConf, ["plugins", "upgrade", PkgName],
          {ok, [{app, Name}, {plugin, PkgName, <<"0.1.3">>}]}
       ).
  
  upgrade_no_args(Config) ->
      try rebar_test_utils:run_and_check(Config, [], ["plugins", "upgrade"], return)
      catch {error, {rebar_prv_plugins_upgrade, no_arg}} ->
          ok
      end,
      ok.
  
  sub_app_plugins(Config) ->
      AppDir = ?config(apps, Config),
  