unison version 2.27.57 (intrepid, available for hardy in hardy-backports) does exactly what you described, in that case it gives a message like 'shortcut: using local file x for y'.
unison version 2.27.57 (intrepid, available for hardy in hardy-backports) does exactly what you described, in that case it gives a message like 'shortcut: using local file x for y'.