anchor.diff:  is_app_available(App, VsnRegex) ->
       case code:lib_dir(App) of
           {error, bad_name} ->
  -            false;
  +            {false, bad_name};
           Path ->
               is_app_available(App, VsnRegex, Path)
       end.
  
positive.code:                         nomatch ->
                              ?WARN("~s has version ~p; requested regex was ~s\n",
                                    [AppFile, Vsn, VsnRegex]),
                              false
                      end;
                  OtherApp ->
                      ?WARN("~s has application id ~p; expected ~p\n", [AppFile, OtherApp, App]),
                      false
              end;
          false ->
              ?WARN("Expected ~s to be an app dir (containing ebin/*.app), but no .app found.\n",
                    [Path]),
              false
      end.
  
  use_source(Dep) ->
  
negative.code:     case is_app_available(App, VsnRegex) of
          {true, AppDir} ->
              find_deps(Rest, {[Dep#dep { dir = AppDir } | Avail], Missing});
          {false, _} ->
              AppDir = filename:join(get_deps_dir(), Dep#dep.app),
              case is_app_available(App, VsnRegex, AppDir) of
                  {true, AppDir} ->
                      find_deps(Rest, {[Dep#dep { dir = AppDir } | Avail], Missing});
                  {false, _} ->
                      find_deps(Rest, {Avail, [Dep#dep { dir = AppDir } | Missing]})
              end
      end;
  