Factorio Forums

What I did when this occured:

I had a bunch of passive provider chests with reinforced conrete I wanted to relocate (around 90k),
so I placed 32 buffer chests, each requesting 4k.

I have around 3800 logistic bots in my network and after most of the material was moved, I noticed many
bots flying to chests that were already completely emptied, just to leave empty handed.

In the screen recording I managed to catch a few of them doing so, but at peak there were several dozens if not hundreds
of these unnecessary trips occuring.

I found this old bug which had been marked as fixed years ago, but it might be the same issue again.
viewtopic.php?p=355573&hilit=empty+prov ... st#p355573
As you can see in the video, these provider chests are linked by inserters, so as one chest gets emptier,
items get transferred out of the chest that is serviced by bots.

My assumption is that due to the inserter, items which are already planned for bot transfers are becoming unavailable.

I have researched stack inserter bonuses and worker bot cargo size and due to the sheer amount of material,
robots have to interrupt their journeys to recharge... maybe some of this is also interfering with the calculations.

Linked bug report is not about robots flying towards empty passive provider, it was about robots deciding to fly towards a mining drill regardless of being unable to get a module from a passive provider and as such that bug report is unrelated.

I am not seeing this behavior to be a bug as it is not harmful to anything and the only solution would be to have robots do more checks: when there were items available in the passive provider chest, some amount of logistic robots were scheduled to pickup those items however you removed the items in the meantime and when robots finally arrived to a chest they saw there are no items to pickup. Your expected behavior is that means that when items would be taken out of a passive provider then robots should stop going towards that passive provider. This would have 2 huge negative consequences: first related to sending robots away where either taking items out of a passive provider would need to find robots scheduled to pickup and send some of them away, or a robot itself would need to periodically check if there are still items to be picked up but this would not be accurate since there may be more robots scheduled to pickup items. Second consequence would be that in case of chests that are often filled and emptied with inserters, it would mean some logistic robots would be constantly requested and cancelled meaning it could happen no robots would reach the chest and as such failing to fulfill any logistic requests.

I am not considering this to be a bug and as such i am moving this topic to Not a bug. Logistic robots are only checking if container has items after arrival and if there are no items inside then they cancel their order. If you do not want this behavior to be happening then do not take items out of passive provider using inserters.