Payment failed flag

There has been work around improving that recently. We're leveraging commerce_log for that. Log entities are created on payment failures (See for example ✨ Add logging for payment failures during checkout Fixed , or 📌 Make it easy to add payment info to \Drupal\commerce_payment\Exception\PaymentGatewayException Active .

Guessing you could somehow using relationships build a view of orders that have logs of a certain type?

Ah thats good news! Yeah I think it would be good to have a new order state for carts which have failed payments like Pending or at least in the cart view have a field which states failed payment or possibly more useful checkout flow state (Order info/Review/Payment) etc.

Seems to me as though there is scope for using both an order state, and the log entities.

While there is nothing stopping anyone from creating a custom workflow featuring a 'Pending' order state, it feels general enough to be useful to have available as a default.

Updating the order state isn't really a good idea, because if the order is no longer a draft, your customer isn't going to be able to resume checkout and it would no longer be an "eligible" cart.