my $mech = WWW::Mechanize->new( autocheck => 0 );
my $res = $mech->get('does.notexist.example');
$res->is_success
    or print "Uhoh\n";

##</code><code>##

my $mech = WWW::Mechanize->new();
my $connected = eval {
    $mech->get('does.notexist.example');
    1
};
if (! $connected) {
    print "Uhoh\n";
};

##</code><code>##

use Try::Tiny;

my $mech = WWW::Mechanize->new();
try {
    $mech->get('does.notexist.example');
} catch {
    print "Uhoh: $_\n";
};