anchor.diff:  cover_compile_engine(Keep_Data) ->
       %% Cover-compile the engine. But first, if the caller asked for it,
       %% export any existing data, because the build will flush them.
  -    MI = ?ENGINE_MOD:module_info(),
  -    Compile = proplists:get_value(compile, MI),
  -    Source  = proplists:get_value(source, Compile),
  -    Options = proplists:get_value(options, Compile),
  -    Export  = filename:rootname(Source) ++ ".coverdata",
  +    MI       = ?ENGINE_MOD:module_info(),
  +    Compile  = proplists:get_value(compile, MI),
  +    Source   = proplists:get_value(source, Compile),
  +    Export   = filename:rootname(Source) ++ ".coverdata",
       Exported = case cover:is_compiled(?ENGINE_MOD) of
           {file, _} when Keep_Data ->
               cover:export(Export, ?ENGINE_MOD),
  
positive.code: compile_engine(File) ->
      Options = [
        verbose,
        return_errors,
        return_warnings
      ],
  
negative.code:         _ ->
              false
      end,
      case cover:compile_beam(?ENGINE_MOD) of
          {ok, _} ->
              ?INFO("Engine cover-compiled~n", []);
          {error, Reason} ->
  