my $d2= ($vx-$ax)*($vx-$ax) + ($vy-$ay)*($vy-$ay);
my $cmp= $best_d2 <=> $d2;
printf $debugfh "%2d,%-2d arch-island-search %5s d2=%4d cc%-2d".
my $d2= ($vx-$ax)*($vx-$ax) + ($vy-$ay)*($vy-$ay);
my $cmp= $best_d2 <=> $d2;
printf $debugfh "%2d,%-2d arch-island-search %5s d2=%4d cc%-2d".