gistfile1.txt

package Foo::A;

use Moose::Role;

requires 'bar';

1;

package Foo::B;

use Moose::Role;

has bar => (
    is      => 'ro',
    isa     => 'HashRef',
);

with 'Foo::A';

1;

package MAIN;

use Moose;

with 'Foo::B';

print "ok\n";

1;