anchor.diff:                 objects = [] :: [file:filename(), ...],
                  opts = [] ::list() | []}).
   
  -compile(Config, _AppFile) ->
  -    case get_specs(Config) of
  +compile(Config, AppFile) ->
  +    case get_specs(Config, AppFile) of
           [] ->
               ok;
           Specs ->
  
positive.code: %% == port_specs ==
  %%
  
  get_specs(Config) ->
      PortSpecs = rebar_config:get_local(Config, port_specs, []),
      Filtered = filter_port_specs(PortSpecs),
      OsType = os:type(),
      [get_port_spec(Config, OsType, Spec) || Spec <- Filtered].
  
  filter_port_specs(Specs) ->
      [S || S <- Specs, filter_port_spec(S)].
  
negative.code:     %% merge with the default for this operating system. This enables
      %% max flexibility for users.
      DefaultEnv  = filter_env(default_env(), []),
  
      %% Get any port-specific envs; use port_env first and then fallback
      %% to port_envs for compatibility
      RawPortEnv = rebar_config:get_list(Config, port_env,
                            rebar_config:get_list(Config, port_envs, [])),
  
      PortEnv = filter_env(RawPortEnv, []),
      Defines = get_defines(Config),
      OverrideEnv = Defines ++ PortEnv ++ filter_env(ExtraEnv, []),
  