use Modern::Perl;
use Data::Dumper;

my $hello = Hello->new->hello($ARGV[0]);

print $hello || warn Dumper $hello->{messages};

package Hello;
use Mojo::Base -base;

sub hello {
  return (pop) ? "successful" : Error->new->error('hello error');
};

package Error;
use Mojo::Base -base;
use overload 'bool' => sub {()};

has messages => sub{[]};

sub error {
  my $self = shift;
  push @{$self->{messages}} => pop;
  return $self;
}