Do not use empty flow control blocks like:
-ifdef(debug). %-define(LOG(X), io:format("{~p,~p}: ~p~n", [?MODULE,?LINE,X])). -else. -define(LOG(X), true). -endif.or
-ifdef(debug). -define(LOG(X), io:format("{~p,~p}: ~p~n", [?MODULE,?LINE,X])). -else. -endif.