use v5.14;
use strict;
use warnings;

package MyObject {
	use Moose;
}

package MyRole {
	use Moose::Role;
	has myattr => (
		is      => 'ro',
		lazy    => 1,
		builder => '_build_myattr',
	);
	sub _build_myattr {
		"value";
	}
}

my $obj = "MyObject"->new;
Moose::Util::apply_all_roles($obj, "MyRole");
say $obj->myattr;

##</code><code>##

# Not this...
default => \&_build_myattr,

# This!
default => sub { shift->_build_myattr(@_) },