why repeated rule output?

From: Larry Evans (jcampbell3_at_[hidden])
Date: 2002-04-01 20:56:42

The following top level Jamfile:
<---------- top Jamfile -------------
project-root
;

rule test-rule
{
ECHO "rule output is" $(TOP) ;
}

test-rule
;
>-------------------------------
produces, with -d+2 option, the following:
<----------- jam d+2 output ----------
rule output is .
rule output is .
>-------------------------------
but I expected just one line.

The jam -v output is:
<----------- jam -v output -----------
Boost.Jam Version 3.1.0. OS=LINUX.
Copyright 1993-2002 Christopher Seiwald and Perforce Software, Inc.
Copyright 2001 David Turner.
Copyright 2001-2002 David Abrahams.
>--------------------------------
This jam was produced from a download of boost
from cvs, as described under the heading "CVS command line access"
on http://www.boost.org/more/download.html.

I'd sure appreciate any help in trying to get jam to work for me.
TIA.