anchor.diff:  
   -include("rebar.hrl").
   
  --ifdef(OTP_RELEASE).
  --if(?OTP_RELEASE < 23).
  --define(ERL_INTERFACE, "-lerl_interface ").
  --endif.
  --endif.
  --ifndef(ERL_INTERFACE).
  --define(ERL_INTERFACE, "").
  --endif.
  +erl_interface() ->
  +    Rel = list_to_integer(erlang:system_info(otp_release)),
  +    if
  +        Rel >= 23 ->
  +            "";
  +        true ->
  +            "-lerl_interface"
  +    end.
  +
  +-define(ERL_INTERFACE, erl_interface()).
  +
   
   -record(spec, {type::'drv' | 'exe',
                  link_lang::'cc' | 'cxx',
  
positive.code:                       ])},
       {"ERL_EI_LIBDIR", lists:concat(["\"", erl_interface_dir(lib), "\""])},
       {"ERL_LDFLAGS"  , "-L$ERL_EI_LIBDIR"},
       {"ERL_LIBS"     , ?ERL_INTERFACE "-lei"},
       {"ERLANG_ARCH"  , rebar_utils:wordsize()},
       {"ERLANG_TARGET", rebar_utils:get_arch()},
  
  
negative.code:        "           CXXFLAGS - C++ compiler~n"
         "           LDFLAGS  - Link flags~n"
         "           ERL_CFLAGS  - default -I paths for erts and ei~n"
         "           ERL_LDFLAGS - default -L and " ++ ?ERL_INTERFACE ++ " -lei~n"
         "           DRV_CFLAGS  - flags that will be used for compiling~n"
         "           DRV_LDFLAGS - flags that will be used for linking~n"
         "           EXE_CFLAGS  - flags that will be used for compiling~n"
  