anchor.diff:  
   %% @spec gen_appup_which_apps([any()],[string()]) -> [any()].
   gen_appup_which_apps(UpgradedApps, [First|Rest]) ->
  -    List = proplists:delete(list_to_atom(First), UpgradedApps),
  +    List = lists:keydelete(list_to_atom(First), 2, UpgradedApps),
       gen_appup_which_apps(List, Rest);
   gen_appup_which_apps(Apps, []) ->
       Apps.
  
positive.code:         [CurrentAppUpApps]),
  
      %% Create a list of apps that don't already have appups
      UpgradeApps = gen_appup_which_apps(UpgradeApps0, CurrentAppUpApps),
      rebar_api:debug("generating .appup for apps: ~p",
          [AddApps ++ UpgradeApps ++ RemoveApps]),
  
  
negative.code:                       [CurrentName, PreviousName]),
  
      %% Find all the apps that have been upgraded
      {AddApps0, UpgradeApps0, RemoveApps} = get_apps(Name,
                                                     PreviousRelPath, PreviousVer,
                                                     CurrentRelPath, CurrentVer,
                                                     State),
  