Thanks Roy!

I have gotten rid of my "Can't call method ... unblessed ref." error. It appears that I was not making copies of the hole objects correctly. Here's what I was doing ...

sub makeLinks {
    ...
    my @nholes = (); 
    for my $nh ($obj->{'board'}->getHoles()) {
        my %newHole = %$_;
    push ( @nholes, \%newHole );
    }
    ...
}
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... and here's what I did to get rid of the error ...

sub makeLinks {
    ...
    my @nholes = (); 
    for my $nh ($obj->{'board'}->getHoles()) {
        push ( @nholes, new hole ( $nh->{'peg'}, $nh->{'holeIndex'}, $
+nh->{'level'}, $nh->{'links'} ));
    }
    ...
}
[download]