[fpc-pascal]writeln in win32 gui application

[vs]

Hi,

The following program gives run time error 103. If I uncomment the
rewrite line, it runs ok. Is this a bug or feature? If it is a feature,
can somebody explain, the reasoning behind it.

program guiwriteln;

{$mode objfpc}{$H+}
{$apptype gui}

begin
  //rewrite(output);
  writeln('Test');
end.

Regards,
Vincent.