Example Usage: 

#!/usr/bin/perl

use 5.014;
use strict;
use warnings;
use autodie;

use FindBin;
use lib $FindBin::Bin . '/lib';
use Devel::Canary;

func_1();

exit;

sub func_1 {
    my $hashref = Devel::Canary->new_hashref;
    func_2($hashref);
}

sub func_2 {
    my($twingle) = @_;
    $twingle->{foo} = 'bar';
}

• Output:

$ ./source/explode 
Fatal attempt to assign to $twingle->{foo} at ./source/explode line 23.
      main::func_2('HASH(0x249dcb8)') called at ./source/explode line 18
      main::func_1() called at ./source/explode line 12