Welcome to the Monastery.

I know nothing about the modules you are trying to use, but perhaps these general debugging techniques will be of use to you (all code is untested).

Use the strictures to help catch common mistakes:

use warnings;
use strict;
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Print out all intermediate values:

use Data::Dumper;
my ($contact) = Denali::Contact->find(contact_id => 1);
print Dumper($contact);
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A quick look at the Devel::Cycle documentation states that:

The find_cycle() function will traverse the object reference and print a report to STDOUT identifying any memory cycles it finds.

So, you should try just:

find_cycle($contact);
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instead of:

print STDOUT find_cycle($contact);
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