use strict;
use warnings;
use lib 't/lib';
use Std;
{
  my ($prem, @res) = eval {
    run_tests(
      sub {
        cmp_deeply([shallow([])], [[]], "bad special");
      }
    );
  };
  like($@, qr/^Found a special comparison in \$data->\[0\]\nYou can only use specials in the expects structure/,
    "bad special");
}