Factorio Forums

What did you do?
I'm trying to replace all the normal quality bots in my network (in this case, on Vulcanus) with legendary bots. I've already staged the legendary bots in a chest next to a roboport, but I wanted to pull the normal ones out first, from the same roboport. To do this, I've put an inserter next to roboport, and requested 500 of each (construction & logistic) bots to go to that roboport, with the thought that this would ultimately pull all of the normal quality bots out, as as soon as a bot lands, it should be pulled out of the roboport and into the chest, and thus the request will never be fully fulfilled, and all the normal quality bots will be pulled out of the network.

What happened?
I'm not entirely sure. All of the logistic bots appear to have been pulled out of the network, but many of the construction bots remain. There's a large group of them above the roboport, that, as best as I can tell, appear to be constantly entering it from the animation (though it's hard to tell with so many bots overlapping one another). However, these bots never actually enter the roboport, and thus, are never removed. The logistic request constantly shows a varying number of bots as "on the way", but they never get there.

What did you expect to happen instead?
The construction robots to enter the roboport.

Does it happen always, once, or sometimes?
I haven't tested yet on other planets, but it still occurs on Vulcanus even after reloading my save. The bots are still in the air and the animation still shows them entering the roboport but never getting in.

Forgot to attach the save file, and it seems I can't edit attachments on the original post, so attaching it here. Just view Vulcanus in remote view and the camera should be almost directly over the problematic roboport.

Also, I noticed a new version was released on Steam since I last launched Factorio, but the issue still occurs on 2.0.21.

Edit: Seems the save file still will not attach, so I've uploaded it here.

Hello, you didn't attach any save file.

Yes, sorry, it doesn't seem to want to attach my save file in the forum for whatever reason. I uploaded it to: https://files.catbox.moe/ewlecu.zip

It seems to be caused by the "500 logistic robots" request, in that it reserves all roboport slots for logistic bots.

Lowering the request to under 301 (i.e. leaving at least one slot for constuction bots) fixed it.

Interesting, as this behavior doesn't happen with logistic chests (i.e. slots in them are not 'reserved' until the item is actually on the way, and are freed up if the item is removed).

Edit: So I've been playing around with this a bit more, and I noticed something not only interesting about the way it's programmed now, but actually useful. With the slots being "reserved" for bots, you can actually use it to "push" the bots out to other roboports in the network when you put them in with an inserter.

For example, when dumping the legendary bots in, I had the problem where the roboport would fill up, and without putting reservations on other roboports, they would never leave until they were needed to fulfill a task. But, if I set a request on the roboport where the bots were being added for, let's say, 50 "normal" quality bots (or basically at least some of a quality/type of bot that isn't in the network at all), the bots being added by the inserter would instead get pushed out to free up that slot for other bots that didn't exist. This is a lot more convenient than setting requests on thousands of roboports, and managing all of those, but I wish there was a way to do this without causing the confusing behavior that resulted in this bug report.

Thank you for reporting this issue. I managed to reproduce it and fix it for 2.0.23.

Thanks for fixing it!