You can catch die's with eval {}, example

#!/usr/bin/perl --
use strict;
use warnings;
use WWW::Mechanize;
my $ua = WWW::Mechanize->new( autocheck => 1 );

for ( 1, 6 ){
    eval {
        $ua->get('die://die');
    1 } or print "$@\n";
}
__END__
Error GETing die://die: Protocol scheme 'die' is not supported at - li
+ne 9

Error GETing die://die: Protocol scheme 'die' is not supported at - li
+ne 9
[download]

Or turn autocheck off, and do your own checking.