Trains get removed from request schedule due to bug

Captain Jeremy wrote:

In other words, when you notice it, going back to the last autosave and checking that that reproduces the issue without any further inputs from you.

Not ignoring you, I've captured at pre-abandoned save and reloaded it, the same thing would not happen again. But after many attempts and watching for it. I have found it happens trains that have only one destination and have the second train is going to arrive significanly after the first. If they come in rapid succession they work fine. It seems like if there is a long pause between the first train and the second arrives while both on their way, the second one may do a re-check and determine its no longer needed. but has no alternate destination so just stops. This difference is frequient in trains that pass choke poiints in my traffic, where the first train may get through and second is stuck in traffic.

I've tried reproducing it as well but haven't been able to reload and reproduce. I believe it is some form of race condition so there maybe be some rng. Maybe I'd have to try harder to get an auto save 30 seconds before it happens but I'm not sure.

Perhaps the right approach is to just make thousands of trains to increase the probability of it happening more frequently.

It would be the worst if the "bug" "fixes itself" after a save re-load.
Like when it would have happened for someone, but only if they wouldn't save & re-load.

Well not really. The schedule and order of trains isn't deterministic

That's what makes me think race condition

we were all wrong.

This just happened even with the requesting station set to 2 trains. Again, this only ever happens on this specific train station, none of the dozens of other train stations on my network nor any other rock requesting station. I do not know why. It happens with NONE of my other stations. It's been aprox 200-300 years since this has happened when I set the request threshold for trains from 3-->2, and that seemingly fixed it, but it just cropped up again. So it's not related to the # of requested trains.

https://drive.google.com/file/d/1B4v5BnaD5l83Mm_8o8PkYqSezUCBGuDl/view?usp=drive_link

save ^

mods

500 years ago I tried demolishing and rebuilding the station from complete scratch- didn't work

Its a fustrating bug, it happens so rare, even if reload a prior save, it likely will not happen again.

seems to be when the second train takes a while after the first

slopth [discord] wrote:

we were all wrong.

I did say this multiple times (maybe not as explicitly, but still):
Trains get removed from request schedule due to bug
Trains get removed from request schedule due to bug
Trains get removed from request schedule due to bug

then why do none of the dozens of other train stations running this EXACT configuration break in this way

it is only ever this specific station

I retain my disagreement that this is a user configuration problem - it should work perfectly fine as designed as there are dozens of other stations running without issue for 2000 years

That I can't tell you, but setting it to 1
would make it impossible to have this happen.

like I know how to ammleriate the symptoms - I'm just trying to find the root of the bug

I'm not sure

I'll test this specific station as 1

but given it just happened at 2, it might still happen

Setting it to 1 train, will fix it and kill the throughput.

Does this train have a fairly long path from pickup to drop?

not the longest route on the network

by probably 30%

raciper [discord] wrote:

Setting it to 1 train, will fix it and kill the throughput.

Then have a stacker right before it.

You either want trains to go there or you don't.

Pick what you want from that, you shouldn't rely
on trains not making to the station fast enough,
as an excuse for increasing the train limit,
past what your station can actually accept physicaly.

Anyways, that is at least true with the current system &
arguing whether or not one should do this is pointless,
because one should do it when the system is as it is.

...

the two trains I had this happened, both had slow frequency between starts and the output would be slow to process. But the path was very conjested. Recycled Glass and Sausages were my two problems. I finally just abandoned the save,

The problem I had is the station was accepting multiple inputs, It could handle 4 trains, but not 4 of the same type.

eryk500 [discord] wrote:

Then have a stacker right before it.

a stacker will not fix the problem as the train is permanantly deackloed until you manually clear it

the station will forever be blocked

I am now going preset paths with each a bypass priority 15 no restriction station

look at the screenshots again - the train has no destination station schedule, it is stuck in the middle of the network with no station it can go to. this is not supposed to happen - ever. a train should always arrive at a destination

eryk500 [discord] wrote:

Then have a stacker right before it.

...

Now I can agree that the game shouldn't "paint itself
into a corner" & even let this scenario "stopping in the
middle of the track after being dispatched" to happen in the first place.

It should recognise that requesting trains to come to it will fill it up,
so it shouldn't over-request trains. The tricky part is that it would
either kill the throughput (like it's mentioned multiple times in this thread),
or there needs to be additional logic that is used to determine just
how much material is being used by the station & only request trains
in such a way that each of them can get serviced.

No amount of configuration, will stop a situation from first train fulfilling the request, in this case he had room for the station to hold two trains but for some reason that train was not wanted. another one got it slot..

Based on the discussion, it seems like the real problem is that during a repathing update the train loses its destination, and cant re-find it due to the station not accepting arrivals