... my @stack = $self->{stack}; ($self->{stacktraces}{join('->',@{$self->{stack}})} = \@stack ) && ... #### ... my @stack = @{ $self->{stack} }; ($self->{stacktraces}{ join('->', @{$self->{stack}}) } = \@stack) && ... #### sub print { use Data::Dump; my $self = shift; dd $self; } #### ... $CSA->TraceFile(\@tracecontent); $CSA->print; ...