require Carp;
Carp::croak "This will produce a compile time error.";

##</code><code>##

 
use Carp;
Carp::croak "This will compile fine.";

##</code><code>##

 
use warnings;
require Carp;
Carp::croak "And so will this.";

##</code><code>##

require Data::Dumper;
print Data::Dumper::Dumper([qw(This is good too)]);