croak when trying to order by average_rating

[SysPete]

Hook error: DBIx::Class::Storage::DBIHacks::_group_over_selection(): Unable to programatically derive a required group_by from the supplied order_by criteria. To proceed either add an explicit group_by, or simplify your order_by to only include plain columns (supplied order_by: 'average_rating') at /home/apm/git/Interchange6-Demo-Shop/DanceShop/bin/../lib/DanceShop.pm line 449
 at /home/apm/.perlbrew/libs/perl-5.20.3@main/lib/perl5/Dancer2/Plugin.pm line 533.

/home/apm/git/Interchange6-Demo-Shop/DanceShop/bin/../lib/DanceShop.pm around line 449


444     # grid view can look messy unless we deliver products in nice rows of

445     # three products per row

446 

447     if ( $results_handler->view eq 'grid' ) {

448         my @grid;

449         my @products = $products->all;

450         while ( my @row = splice( @products, 0, 3 ) ) {

451             push @grid, +{ row => \@row };

452         }

453         $tokens->{products} = \@grid;

454     }