Factorio Forums

What did you do?
In a spidertron inventory, in remote view, right-click on multiple stacks of items of different types to apply deconstruction crosses.

What happened?
As items are carried away by construction bots, the inventory is automatically sorted. This causes items to move into earlier slots. As this happens any remaining deconstruction crosses do not move to follow the stack they were originally removing, but instead stay over the slots they were originally pointing at. This may now contain a different type of item. Construction bots will then start removing those items, instead of the ones instructed.

The wrong types of items, and sometimes the wrong number of items, may be removed.

If many deconstruction crosses are used at the same time this can get very messy, entriely the wrong items end up being removed.

What did you expect to happen instead?
Behaviourally: For each right-click, construction bots should eventually carry away exactly the number of items that were in that slot at the moment that it was right-clicked on. Unless that type of items runs out for some other reason before the construction bots can collect that number of items.
Visually: The deconstruction crosses should attempt to follow stacks of items as they move.

Does it happen always, once, or sometimes?
Always

Discussion
There seems to be a related issue with deconstruction crosses in roboports. While a deconstruction cross is active bots can fly away, or new bots can arrive. This leads to very confusing behavour. I do not know how many bots are actually deconstructed in this case. Often, the deconstruction cross can get stuck pointing at an empty inventory slot and won't go away. Closing the roboport and opening it again clears the stuck deconstruction cross.

Stuck deconstruction crosses on empty slots can also happen in spidertrons, although it seems to clear itself quickly without closing the inventory.

This issue implies that there could be issues with non-sorting inventories as well (such as chests and trains). If an inserter or logistics bots are adding or removing items from the inventory while a deconstruction cross is active the wrong number of items may be carried away by construction bots, although I have not tested this yet.

Video example of this and other issues with ghost stacks in vehicles:

https://cloud.hisui.moe/s/kyzLBXCKyL7sYjp

That video captures it perfectly.
I think roboports also have the same issue with requested items shown in the video.

I just noticed that cargo landing pads also have self-sorting inventories too. However the behaviour seems different. So far I haven't been able to reproduce the same issues as with spidertrons.

[2.0.19]

The issue with Spidertron:


And here it is with a landing pad:



It would appear the cross on the landing pad moves to first stack of same item as soon as bots start to remove them, and does the same to another cross once a stack is depleted, which results in weirdly migrating crosses along that entire item line. However, other than looking weird, it does seem to only transfer correct items and doesn't leave empty slots with deconstruction orders.

Thanks for the report. In 2.0.23 spidertrons will behave the same way as cargo landing pads.