Dwarf Fortress Bug Tracker - Dwarf Fortress
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0001254Dwarf FortressPathfindingpublic2010-04-16 16:392015-12-15 13:13
Toady One 
0001254: When cavern is breached, web collection pathfinding spams with "unable to find path"
When 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.
Open a cavern with webs and have a weaver.
I 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.
No tags attached.
has duplicate 0001336resolved Footkerchief Pathfinding problems when hit caves or cavern 
has duplicate 0001369resolved Footkerchief Could not find path gathering cave spider webs in the undergrounds 
has duplicate 0001744closed Logical2u "Collect Webs" job always results in pathfinding error 
has duplicate 0004438resolved Footkerchief Hunters cancel hunt: No path after accessing first cavern 
has duplicate 0004876resolved Knight Otu Dwarves have difficulty pathing to webs in the caverns 
has duplicate 0002150closed Footkerchief Weaver can not find path to webs when door unrelated to path to webs is forbidden, or may be confusing his jobs 
has duplicate 0003835resolved Dwarfu Dwarf tried to collect thread and then cancels task: "unable to find path" 
has duplicate 0007536resolved Dwarfu fortress stuck in pathfinding failure 
related to 0001455resolved Footkerchief Auto-web collection set to 'off' not working 
related to 0001319resolved Toady One Pathfinding problems after lowest cavern layer is breached 
related to 0002469resolved Toady One If burrow includes unrevealed webs, dwarves try to collect the (inaccessible) webs and spam cancellations 
related to 0002869confirmed Dwarfu Massive "item inaccessible"/"could not find path" spam results from hauling jobs targeting unrevealed items 
related to 0003873resolved Dwarfu dwarves will stop pathing through stairs in obsidan 
related to 0004372resolved Toady One occasionally get negative distance value for materials for constructions 
related to 0005634acknowledged Dwarfu 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 0001190resolved Dwarfu Dwarf cancels Eat: Cannot find path 
related to 0006556resolved Footkerchief Dwarf attempting to path to unknown (likely belowground) webs. 
related to 0007991resolved Footkerchief Weaver won't climb tree to collect webs 
Issue History
2010-04-16 16:39slinkNew Issue
2010-04-16 17:14FootkerchiefNote Added: 0003921
2010-04-18 17:15slinkNote Added: 0004145
2010-04-19 10:52FootkerchiefRelationship addedparent of 0001336
2010-04-20 10:58FootkerchiefRelationship addedparent of 0001369
2010-04-23 11:02FootkerchiefRelationship addedrelated to 0001455
2010-04-27 14:33FootkerchiefRelationship addedrelated to 0001319
2010-04-27 14:33FootkerchiefSticky IssueNo => Yes
2010-04-27 15:17barconisNote Added: 0005415
2010-05-04 14:13riznarNote Added: 0006118
2010-05-04 17:40Logical2uRelationship addedhas duplicate 0001744
2010-05-10 20:35Keldor314Note Added: 0006535
2010-05-26 03:49peregarrettNote Added: 0007336
2010-05-26 03:50peregarrettNote Edited: 0007336bug_revision_view_page.php?bugnote_id=0007336#r2753
2010-06-04 13:04DwarfuNote Added: 0007671
2010-06-04 13:04DwarfuIssue Monitored: Dwarfu
2010-06-25 11:21FootkerchiefRelationship addedrelated to 0002469
2010-07-08 07:15dai-rasaNote Added: 0009785
2010-07-08 07:19dai-rasaIssue Monitored: dai-rasa
2010-07-08 10:46KanddakNote Added: 0009795
2010-07-10 15:16KumquatNote Added: 0009889
2010-07-11 10:07ProfligateIssue Monitored: Profligate
2010-07-28 20:27FootkerchiefRelationship addedrelated to 0002869
2010-10-23 02:01mazterlithNote Added: 0013477
2010-12-11 12:55FootkerchiefRelationship addedrelated to 0002713
2011-01-06 13:57FootkerchiefRelationship addedrelated to 0003873
2011-03-20 15:07DoradanNote Added: 0016389
2011-03-21 02:12AnotherNote Added: 0016409
2011-03-25 07:01Kaelem GaenNote Added: 0016569
2011-03-25 07:02Kaelem GaenIssue Monitored: Kaelem Gaen
2011-03-25 07:48Malibu StaceyNote Added: 0016572
2011-03-28 18:52FootkerchiefRelationship addedrelated to 0004372
2011-03-28 18:53FootkerchiefSummaryWhen 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 12:40FootkerchiefRelationship addedhas duplicate 0004438
2011-04-03 15:52jazzeraintNote Added: 0017028
2011-04-04 01:56InsanityPreludeNote Added: 0017044
2011-04-04 01:56InsanityPreludeIssue Monitored: InsanityPrelude
2011-09-03 14:34Knight OtuRelationship addedhas duplicate 0004876
2011-10-26 14:27thistleknotNote Added: 0018913
2012-01-30 10:42ninjanomnomNote Added: 0019430
2012-02-20 11:21haxsIssue Monitored: haxs
2012-02-27 08:40Granite26Note Added: 0020799
2012-03-06 09:24FootkerchiefRelationship deletedrelated to 0002713
2012-03-06 09:25FootkerchiefRelationship replacedhas duplicate 0001336
2012-03-06 09:25FootkerchiefIssue Monitored: Footkerchief
2012-03-06 09:25FootkerchiefIssue Monitored: svancouw
2012-03-06 09:25FootkerchiefRelationship replacedhas duplicate 0001369
2012-03-06 09:25FootkerchiefIssue Monitored: etherflan
2012-03-06 09:27FootkerchiefRelationship addedhas duplicate 0002150
2012-03-06 09:27FootkerchiefRelationship addedhas duplicate 0003835
2012-03-07 18:19QmarxNote Added: 0021245
2012-03-08 08:44KijiroNote Added: 0021262
2012-03-14 09:06FootkerchiefRelationship addedrelated to 0005634
2012-04-04 17:05daenythNote Added: 0022089
2012-04-04 17:05daenythIssue Monitored: daenyth
2012-04-23 08:22KonNote Added: 0022352
2012-04-23 08:54FootkerchiefRelationship addedrelated to 0005830
2012-06-18 10:50FootkerchiefRelationship addedrelated to 0001190
2014-07-07 21:44FootkerchiefRelationship addedrelated to 0006556
2014-07-21 07:12FootkerchiefRelationship addedrelated to 0007536
2014-07-26 07:01DwarfuRelationship replacedhas duplicate 0007536
2014-07-26 07:02DwarfuNote Added: 0027595
2014-07-26 07:02DwarfuAssigned To => Dwarfu
2014-07-26 07:02DwarfuStatusnew => acknowledged
2014-07-31 06:28KirkegaardNote Added: 0028023
2014-07-31 06:28KirkegaardIssue Monitored: Kirkegaard
2014-07-31 12:57DwarfuStatusacknowledged => confirmed
2014-08-01 13:32Toady OneNote Added: 0028096
2014-08-01 13:32Toady OneStatusconfirmed => resolved
2014-08-01 13:32Toady OneFixed in Version => Next Version
2014-08-01 13:32Toady OneResolutionopen => fixed
2014-08-01 13:32Toady OneAssigned ToDwarfu => Toady One
2014-08-01 14:05KirkegaardIssue End Monitor: Kirkegaard
2014-08-01 15:52DwarfuIssue End Monitor: Dwarfu
2014-08-13 12:16FootkerchiefRelationship addedrelated to 0007991
2014-09-14 09:43lethosorSticky IssueYes => No
2014-11-25 22:56InsanityPreludeIssue End Monitor: InsanityPrelude
2015-12-15 13:13Kaelem GaenIssue End Monitor: Kaelem Gaen

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. http://dffd.wimbli.com/ [^]
2010-04-18 17:15   
http://dffd.wimbli.com/file.php?id=2150 [^]

I remembered that I also have PET_EXOTIC changed to PET for warthogs, but that doesn't seem like it should affect pathfinding.
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.
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.
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.
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

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.
2010-07-08 07:15   
Confirming this for 0.31.08 as well.

Related save game: http://dffd.wimbli.com/file.php?id=2643 [^]

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.
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).
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.
2010-10-23 02:01   
So forbid the unreachable and the unseeable webs and the damned spamming will stop? Finally...
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.
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   
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   
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.
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?
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.
2011-10-26 14:27   
I had this issue as well.

My original problem was in

http://www.bay12forums.com/smf/index.php?topic=95360.msg2712265#msg2712265 [^]

I have a save on

http://www.mediafire.com/?vxv4pvso80z6mgq [^]

using civ forge 2.42

http://dffd.wimbli.com/file.php?id=4845 [^]

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.
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?
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.
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.

http://dffd.wimbli.com/file.php?id=5810 [^]
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.
2012-04-04 17:05   
I can confirm this happens on .06

Do you need a save uploaded?
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.
2014-07-26 07:02   
40.04 save from martinuzz in 0007536:
http://dffd.wimbli.com/file.php?id=9103 [^]
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   
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.