# does *NOT* die when this is not imported - importing
# and using this is what triggers the COP->cop_warnings to be bad.
use B::Utils qw'walkallops_simple'; 
use B::Generate; 

$\ = "\n";
$| = 1;

print "$_ " . $_->VERSION for qw( B B::Utils B::Generate );
B::Utils::walkallops_simple( \ &cb );

sub cb
{
    my $op = shift;
    my $addr = $$op;
    return unless $op=~/COP/;

    my $w = unpack('H*', unpack "P", pack 'L', $addr + 48);
    return if $w eq "00";
    print $w;
    print unpack 'H*', unpack 'P56', pack 'L', $addr;
    print $op->file . ":" . $op->line;

    print $op->warnings; # SEGFAULT HERE
}