use strict;
use warnings;
use Carp;

# Configure the warn signal handler to print the stack trace provided by Carp.
$SIG{__WARN__} = sub {print STDERR Carp::longmess(@_); };

run();

sub run {
    my $code = eval 'sub {
        my $a = 1 - undef;
    };';
    $code->();
}