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IDProjectCategoryView StatusDate SubmittedLast Update
0001254Dwarf FortressPathfindingpublic2010-04-16 16:392015-12-15 13:13
Assigned ToToady One 
PlatformOSOS Version
Product Version0.31.03 
Target VersionFixed in Version0.40.06 
Summary0001254: When cavern is breached, web collection pathfinding spams with "unable to find path"
DescriptionWhen I opened a cavern which contained webs, I began to be spammed by messages from my weavers that they could not find a path to collect the webs. The fact that there was a path was demonstrated by the arrival of troglodytes into my main tunnels at a later time. I cancelled that game via Task Manager and reloaded from a save.

The second time I opened those caverns, I got the spam again. This time I quickly walled off the staircase from the caverns. One of the supposedly unreachable webs was destroyed by my mason as he was building the walls. Once the walls were completed, the spamming stopped.

I'm calling that a replication even though it was the same fortress, just reloaded. The world was generated in 31.03 and my only mods at the moment are for gender-specific animal names.
Steps To ReproduceOpen a cavern with webs and have a weaver.
Additional InformationI am sorry if this duplicates other reports. I tried to find something like it, but most pathfinding bug reports were marked resolved and/or didn't seem quite the same to me.
TagsNo tags attached.
Attached Files

- Relationships
has duplicate 0001336resolvedFootkerchief Pathfinding problems when hit caves or cavern 
has duplicate 0001369resolvedFootkerchief Could not find path gathering cave spider webs in the undergrounds 
has duplicate 0001744closedLogical2u "Collect Webs" job always results in pathfinding error 
has duplicate 0004438resolvedFootkerchief Hunters cancel hunt: No path after accessing first cavern 
has duplicate 0004876resolvedKnight Otu Dwarves have difficulty pathing to webs in the caverns 
has duplicate 0002150closedFootkerchief Weaver can not find path to webs when door unrelated to path to webs is forbidden, or may be confusing his jobs 
has duplicate 0003835resolvedDwarfu Dwarf tried to collect thread and then cancels task: "unable to find path" 
has duplicate 0007536resolvedDwarfu fortress stuck in pathfinding failure 
related to 0001455resolvedFootkerchief Auto-web collection set to 'off' not working 
related to 0001319resolvedToady One Pathfinding problems after lowest cavern layer is breached 
related to 0002469resolvedToady One If burrow includes unrevealed webs, dwarves try to collect the (inaccessible) webs and spam cancellations 
related to 0002869confirmedDwarfu Massive "item inaccessible"/"could not find path" spam results from hauling jobs targeting unrevealed items 
related to 0003873resolvedDwarfu dwarves will stop pathing through stairs in obsidan 
related to 0004372resolvedToady One occasionally get negative distance value for materials for constructions 
related to 0005634acknowledgedDwarfu Hunters spam with "can`t find path" because of unaccessible creature 
related to 0005830new Webs from Giant Cave Spider floating in the air. 
related to 0001190resolvedDwarfu Dwarf cancels Eat: Cannot find path 
related to 0006556resolvedFootkerchief Dwarf attempting to path to unknown (likely belowground) webs. 
related to 0007991resolvedFootkerchief Weaver won't climb tree to collect webs 

-  Notes
Footkerchief (manager)
2010-04-16 17:14

Yeah, it seems like there are still some lingering problems with pathfinding -- see 0001137. A save would probably be helpful for this one. Bonus points if the digging designating is already marked. [^]
slink (reporter)
2010-04-18 17:15 [^]

I remembered that I also have PET_EXOTIC changed to PET for warthogs, but that doesn't seem like it should affect pathfinding.
barconis (reporter)
2010-04-27 15:17

I've seen this happen in 31.03, although it eventually stopped for me. I suspect it has something to do with the web selection part of the job, because I've noticed dwarves running to collect distant webs when there are much closer webs available. Maybe (totally guessing here) a web is picked that is in an opened cavern but not in a revealed area of that cavern, or that can't be reached by a path that runs through the revealed area. It's not uncommon to see a piece of cavern that's cut off from everything else, just because you happened to break into another square section.
riznar (reporter)
2010-05-04 14:13

A workaround I got from barconis's post is to dig into isolated sections of the cavern and/or forbid webs you think are isolated. It stopped shortly after I did this.
Keldor314 (reporter)
2010-05-10 20:35

Yeah, it looks like dwarves can't path to something through undiscovered terrain. I had this problem when they wanted to eat some cave fish belonging to a local tribe of lizardmen.
peregarrett (reporter)
2010-05-26 03:49
edited on: 2010-05-26 03:50

Experienced that. When I moved the loom closer to cavern entrance, weaver started to work. Wood cutters were cutting trees there withoun any problems, though...

ver 31.04

Dwarfu (manager)
2010-06-04 13:04

Confirmed 0.31.05.

Farmers, woodcutters and herbalists path just fine.

It does seem that web collection is trying to collect webs that they shouldn't know are there and/or can't reach.

I forbid all webs except the ones I could see AND they could get to - the message spam stopped.
dai-rasa (reporter)
2010-07-08 07:15

Confirming this for 0.31.08 as well.

Related save game: [^]

Originally the cavern location that was closed off by a 1 square ridge. By digging away 2 squares the cancel messages stopped. This would be at zoom location 4 (F4) and then up one level.

By closing a bridge, you can trigger the messages again. Provided the dwarf is on the right side.

The lever for the bridge is at zoom level 3 (F3), the right one of the two.

The bridge is currently open, so you should get the message right away.
Hope it helps.
Kanddak (reporter)
2010-07-08 10:46

I've had my web collectors do this, and more recently I had a seemingly related issue with a woodcutter. I decided to clearcut a recently discovered cavern, blanketed it with woodcutting designations, and then observed the woodcutter repeatedly picking up a job to cut a specific tree which I hadn't revealed a path to yet, then cancelling with unable to find path. It seemed as if the game knew there was a path when it assigned the job, but the woodcutter didn't know and cancelled it (hundreds of times).
Kumquat (reporter)
2010-07-10 15:16

Actually the case seems to be the opposite.

10 The job system apparently does not know if an undiscovered square is pathable, assumes it is, and assigns a job there.

20 The dwarf tries to find a job, and fails.

30 The dwarf gets another job.

40 GOTO 10.
mazterlith (reporter)
2010-10-23 02:01

So forbid the unreachable and the unseeable webs and the damned spamming will stop? Finally...
Doradan (reporter)
2011-03-20 15:07

If a Giant Toad shows up and is the highest priority hunting taget, hunters will spam inacessable messages if it dives into the water. If it comes out, everything is fine though.
Another (reporter)
2011-03-21 02:12

Hunters also spam this if all possible hunting targets are airborne and currently above ground (or cavern ground) level.

They still shoot at birds in the air OK if they are within range but they need to path to the exact tile of their prey for their job to start.
Kaelem Gaen (reporter)
2011-03-25 07:01

Seems this started happening again in 31.22, granted I'm using a 31.21 save in it,
I get it with only the first cavern breached, after I had carved a route to some that were unreachable
Malibu Stacey (reporter)
2011-03-25 07:48

duplicate of 0001074.

The core issue is that dwarves don't use pathfinding when choosing an item for a job, they just pick the one which is the fewest tiles away. This item can be completely inaccessible or hundreds of steps away from another perfectly valid item when Z levels are involved. I've had dwarves run out of the fort to get some wood I chopped on the surface so I could build a windmill because it was 2 Z levels above the stockpile they were trying to fill even though they passed the trade depot on the way which had loads of wood logs which I'd just bought from a caravan.

Easy way to show this, on Z place a masons workshop. Say 5 tiles away make a stone stockpile. On Z-1 or Z+1 place a stone stockpile directly underneath or above the masons workshop. Make the access between Z levels a few hundred tiles away. Now queue a Make Rock Blocks job on repeat & watch as your dwarf ignores the stockpile near him/her & run all the way to the next Z level to get the stone it (stupidly) thinks is closer.
jazzeraint (reporter)
2011-04-03 15:52

Getting this on .25, dwarf trying to collect webs on the surface that are completely accessible... yet inaccessible spam.

Tried forbidding almost all webs on the surface. There's a cave on my map that probably extends down into the caverns, so I'm guessing the dwarf is trying to grab webs that aren't even visible through said cave?
InsanityPrelude (reporter)
2011-04-04 01:56

Web thing's still happening, and in this most recent fort, so is my miners refusing to dig into any open area of the second cavern layer. Chunks of rock in the middle of the underground sea are fine, but if I try to dig into an open area to gather plants, the job gets canceled.

I have a save demonstrating this if anyone needs it.
thistleknot (reporter)
2011-10-26 14:27

I had this issue as well.

My original problem was in [^]

I have a save on [^]

using civ forge 2.42 [^]

The z-levels I'm having issues on are: 117 (can't build two up/down stairwells between the two levels)


if I try to remove the wall on z-level 131 (next to the stairwell next to some spike traps) , I get can't find path errors.
ninjanomnom (reporter)
2012-01-30 10:42

I had this same problem, although i had no problem after i moved the loom closer to the caves. Maybe your loom is too far away?
Granite26 (reporter)
2012-02-27 08:40

I've seen similar issues that seem to be caused by too much foot traffic. The longer the path, the more likely there's a spot on the path covered by two dwarves standing on top of each other.
Qmarx (reporter)
2012-03-07 18:19

I've currently got this bug with a hunter who keeps canceling hunt, cannot find path. I embarked on a lair, and I think he's trying to hunt things in the unrevealed cave areas. [^]
Kijiro (reporter)
2012-03-08 08:44

If you go to the loom you can suspend the workshop action "Collect Webs". This isn't a fix obviously, but it will stop your dwarves from spamming you.

I haven't figured out how to get the hunters to stop spamming me with 'cancels hunt: could not find path'. I agree though that the likely culprit is undiscovered cave paths. I am having the hunter spam problem much less frequently now that I have explored the caverns of my fortress more. I've also noticed my hunters frequently go down to the caves to shoot at Trogdolytes.
daenyth (reporter)
2012-04-04 17:05

I can confirm this happens on .06

Do you need a save uploaded?
Kon (reporter)
2012-04-23 08:22

I'm having this problem in 34.07. If I set web collection either through the manager or the loom, I get the can't find path spam. It may be that my pet Giant Cave Spider shot webs at an FB that flew over the walls of my fort resulting in webs floating in the air.
Dwarfu (manager)
2014-07-26 07:02

40.04 save from martinuzz in 0007536: [^]
Kirkegaard (reporter)
2014-07-31 06:28

Got this issue in .5, problem is easy to solve by creating a burrow since they seem to try to get the silk longest away first (also if they can't get it) instead of starting with the silk just near the entrance.
Toady One (administrator)
2014-08-01 13:32

This one is difficult, because they are trying to get to stuff that is accessible, but requires pathing through unexplored tiles. I can't redo the connectivity map or lots of other stuff will break, so what I've done is made a job failure of this kind silently forbid the web in question, provided the web is actually accessible (same component). So if you explore later, you can unforbid the web and collect it.

The part that is confusing now will be that webs will become forbidden and people won't know why. I need some kind of new unobtrusive notice to solve this problem (like the combat report indicators probably), so that your main announcements aren't spammed for each web but you still know that something happened.

- Issue History
Date Modified Username Field Change
2010-04-16 16:39 slink New Issue
2010-04-16 17:14 Footkerchief Note Added: 0003921
2010-04-18 17:15 slink Note Added: 0004145
2010-04-19 10:52 Footkerchief Relationship added parent of 0001336
2010-04-20 10:58 Footkerchief Relationship added parent of 0001369
2010-04-23 11:02 Footkerchief Relationship added related to 0001455
2010-04-27 14:33 Footkerchief Relationship added related to 0001319
2010-04-27 14:33 Footkerchief Sticky Issue No => Yes
2010-04-27 15:17 barconis Note Added: 0005415
2010-05-04 14:13 riznar Note Added: 0006118
2010-05-04 17:40 Logical2u Relationship added has duplicate 0001744
2010-05-10 20:35 Keldor314 Note Added: 0006535
2010-05-26 03:49 peregarrett Note Added: 0007336
2010-05-26 03:50 peregarrett Note Edited: 0007336 View Revisions
2010-06-04 13:04 Dwarfu Note Added: 0007671
2010-06-04 13:04 Dwarfu Issue Monitored: Dwarfu
2010-06-25 11:21 Footkerchief Relationship added related to 0002469
2010-07-08 07:15 dai-rasa Note Added: 0009785
2010-07-08 07:19 dai-rasa Issue Monitored: dai-rasa
2010-07-08 10:46 Kanddak Note Added: 0009795
2010-07-10 15:16 Kumquat Note Added: 0009889
2010-07-11 10:07 Profligate Issue Monitored: Profligate
2010-07-28 20:27 Footkerchief Relationship added related to 0002869
2010-10-23 02:01 mazterlith Note Added: 0013477
2010-12-11 12:55 Footkerchief Relationship added related to 0002713
2011-01-06 13:57 Footkerchief Relationship added related to 0003873
2011-03-20 15:07 Doradan Note Added: 0016389
2011-03-21 02:12 Another Note Added: 0016409
2011-03-25 07:01 Kaelem Gaen Note Added: 0016569
2011-03-25 07:02 Kaelem Gaen Issue Monitored: Kaelem Gaen
2011-03-25 07:48 Malibu Stacey Note Added: 0016572
2011-03-28 18:52 Footkerchief Relationship added related to 0004372
2011-03-28 18:53 Footkerchief Summary When Cavern Opened Web Collection Pathfinding Spams With Unable To Find Path => When cavern is breached, web collection pathfinding spams with "unable to find path"
2011-04-03 12:40 Footkerchief Relationship added has duplicate 0004438
2011-04-03 15:52 jazzeraint Note Added: 0017028
2011-04-04 01:56 InsanityPrelude Note Added: 0017044
2011-04-04 01:56 InsanityPrelude Issue Monitored: InsanityPrelude
2011-09-03 14:34 Knight Otu Relationship added has duplicate 0004876
2011-10-26 14:27 thistleknot Note Added: 0018913
2012-01-30 10:42 ninjanomnom Note Added: 0019430
2012-02-20 11:21 haxs Issue Monitored: haxs
2012-02-27 08:40 Granite26 Note Added: 0020799
2012-03-06 09:24 Footkerchief Relationship deleted related to 0002713
2012-03-06 09:25 Footkerchief Relationship replaced has duplicate 0001336
2012-03-06 09:25 Footkerchief Issue Monitored: Footkerchief
2012-03-06 09:25 Footkerchief Issue Monitored: svancouw
2012-03-06 09:25 Footkerchief Relationship replaced has duplicate 0001369
2012-03-06 09:25 Footkerchief Issue Monitored: etherflan
2012-03-06 09:27 Footkerchief Relationship added has duplicate 0002150
2012-03-06 09:27 Footkerchief Relationship added has duplicate 0003835
2012-03-07 18:19 Qmarx Note Added: 0021245
2012-03-08 08:44 Kijiro Note Added: 0021262
2012-03-14 09:06 Footkerchief Relationship added related to 0005634
2012-04-04 17:05 daenyth Note Added: 0022089
2012-04-04 17:05 daenyth Issue Monitored: daenyth
2012-04-23 08:22 Kon Note Added: 0022352
2012-04-23 08:54 Footkerchief Relationship added related to 0005830
2012-06-18 10:50 Footkerchief Relationship added related to 0001190
2014-07-07 21:44 Footkerchief Relationship added related to 0006556
2014-07-21 07:12 Footkerchief Relationship added related to 0007536
2014-07-26 07:01 Dwarfu Relationship replaced has duplicate 0007536
2014-07-26 07:02 Dwarfu Note Added: 0027595
2014-07-26 07:02 Dwarfu Assigned To => Dwarfu
2014-07-26 07:02 Dwarfu Status new => acknowledged
2014-07-31 06:28 Kirkegaard Note Added: 0028023
2014-07-31 06:28 Kirkegaard Issue Monitored: Kirkegaard
2014-07-31 12:57 Dwarfu Status acknowledged => confirmed
2014-08-01 13:32 Toady One Note Added: 0028096
2014-08-01 13:32 Toady One Status confirmed => resolved
2014-08-01 13:32 Toady One Fixed in Version => Next Version
2014-08-01 13:32 Toady One Resolution open => fixed
2014-08-01 13:32 Toady One Assigned To Dwarfu => Toady One
2014-08-01 14:05 Kirkegaard Issue End Monitor: Kirkegaard
2014-08-01 15:52 Dwarfu Issue End Monitor: Dwarfu
2014-08-13 12:16 Footkerchief Relationship added related to 0007991
2014-09-14 09:43 lethosor Sticky Issue Yes => No
2014-11-25 22:56 InsanityPrelude Issue End Monitor: InsanityPrelude
2015-12-15 13:13 Kaelem Gaen Issue End Monitor: Kaelem Gaen

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