Factorio Forums

When you schedule an upgrade with a planner, in my case a bulk inserter being replaced by a fast inserter, then the original entity gets destroyed before the new one replaced it, the ghost entity that is placed by the game to be reconstructed is still the original entity (the bulk inserter) but it has the upgrade already planned on it and is recognized as the upgraded entity (the fast inserter). This then requires the bots to first build the bulk inserter and then replace it again with a fast inserter, or in the worst case scenario be stuck in the same limbo over and over again if the original level entity (the bulk inserter after it's been placed again) is destroyed before the upgrade could be placed.

In this picture you can see the described in action, the construction entity ghost there is for a bulk inserter but the upgrade planner recognizes it as a fast inserter:

Thanks for the report. This behavior of entity to be upgraded dying into a ghost of original entity with upgrade scheduled on it is (as i remember it) fully intentional decision.

First reason why this behavior was added is due to underground belts, since when they are ordered to upgrade, they cut both old and new undergrounds. If entity dying would cause the upgrade to be instantly applied onto entity ghost, this would cause one of those underground types to no longer by cut by the underground leading to problems with other end of underground possibly connecting to wrong ends and causing items to go where they should not. Additionally both ends of such underground must match with their current type and upgraded type for certain fast replace operations to take place on both ends.

Second reason for this behavior is that players were often using upgrade planner over large area of a factory causing the item to build upgraded entity not be readily available, as such it was decided its better to first build the original entity first and once this is done request the upgrade to what may or may not be available.

Because of that i am closing this as Not a bug.

Thank you for the fast response, I didn't even think about underground belts yeah this makes a lot of sense then.