Dwarf Fortress Bug Tracker - Dwarf Fortress
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IDProjectCategoryView StatusDate SubmittedLast Update
0001566Dwarf FortressPathfindingpublic2010-04-26 21:132012-04-02 12:01
ReporterDraco18s 
Assigned ToFootkerchief 
PrioritynormalSeveritymajorReproducibilityhave not tried
StatusresolvedResolutionunable to reproduce 
PlatformOSOS Version
Product Version 
Target VersionFixed in Version 
Summary0001566: Constructed Up-Down Stairs over Natural Downstairs render "Down" an Invalid Path
DescriptionOr at least, that is what I believe caused the issue. I accidentally [d][z]'d some up-down stairs, leaving me with "down stairs" and stranding at least one dwarf. So I constructed some Up-Down stairs on the tile, which thankfully reconnected it with the surface.

However, none of my dwarves could access the level below (nor could ones below get out), leading to much frustration. Deconstructing the stairs and building Up stairs didn't help (only registered up as valid), and the tile was in just the right place that I never succeeded in channeling the stairs out (some not-miner always went and deconstructed the stairs; didn't try to work around that before I gave up on the fort and [attempted] to flood hell with magma, relatively uneventfully--I swear the red * are support AND open space).
Steps To ReproduceDig up-down stairs.
Remove with [d][z].
Build up-down stairs on top of a natural downstair.
Attempt to get a path from top to bottom
Additional Information
Tagsconstruction, Intentional/Expected?, pathfinding
Relationships
child of 0000470resolved Footkerchief Up/down stairs break pathfinding. 
Attached Files
Issue History
Date ModifiedUsernameFieldChange
2010-04-26 21:13Draco18sNew Issue
2010-04-26 21:26FootkerchiefTag Attached: Intentional?
2010-04-26 22:09DoctorZuberNote Added: 0005283
2010-04-27 02:35MalicusNote Added: 0005315
2010-04-27 03:35king doomNote Added: 0005327
2010-04-27 03:38AreyarTag Attached: construction
2010-04-27 03:38AreyarTag Attached: pathfinding
2010-04-27 03:54MalicusNote Added: 0005328
2010-04-27 10:31Draco18sNote Added: 0005355
2010-04-27 10:32Draco18sNote Edited: 0005355bug_revision_view_page.php?bugnote_id=0005355#r1909
2010-04-27 13:46MalicusNote Added: 0005387
2010-04-28 06:03hyndisNote Added: 0005512
2010-04-28 06:58ercdvsNote Added: 0005521
2010-04-28 09:24FootkerchiefNote Added: 0005542
2010-04-28 09:24FootkerchiefIssue Monitored: Footkerchief
2010-04-28 09:30DoctorZuberNote Added: 0005545
2010-04-28 09:30DoctorZuberNote Edited: 0005545bug_revision_view_page.php?bugnote_id=0005545#r2021
2010-04-28 09:34DoctorZuberNote Edited: 0005545bug_revision_view_page.php?bugnote_id=0005545#r2022
2010-04-28 09:34DoctorZuberNote Edited: 0005545bug_revision_view_page.php?bugnote_id=0005545#r2023
2010-04-28 10:35DoctorZuberNote Added: 0005551
2010-07-12 12:03FootkerchiefTag RenamedIntentional? => Intentional/Expected?
2011-07-02 23:38DwarfuRelationship addedchild of 0000470
2012-04-02 12:01FootkerchiefStatusnew => resolved
2012-04-02 12:01FootkerchiefResolutionopen => unable to reproduce
2012-04-02 12:01FootkerchiefAssigned To => Footkerchief

Notes
(0005283)
DoctorZuber   
2010-04-26 22:09   
Does an alternate path exist when you're nuking these stairs?

For placing constructed up/down stairs I find you have to channel the space out to remove the floor otherwise it cannot path down. This much is consistent with 40d behavior.
(0005315)
Malicus   
2010-04-27 02:35   
Odd. I just dug up/down stairs with up stairs below them, d->z'ed over the up/down stairs, then constructed up stairs over the down stairs that remained. I designated a spot to mine on the level with the up stairs below the constructed up/downs (with the newly constructed up/downs being the only path to get there), and my miners had no trouble getting down there to mine. So... cannot reproduce while embarking specifically to test this.
(0005327)
king doom   
2010-04-27 03:35   
What DF version are you using?
(0005328)
Malicus   
2010-04-27 03:54   
31.03, in my test.
(0005355)
Draco18s   
2010-04-27 10:31   
(edited on: 2010-04-27 10:32)
DoctorZuber:
No, an alternate path did not exist, that's why I was having such an issue.

Malicus:
If you can't reproduce, then there must have been some other factor involved. I haven't had the time to go about trying to reproduce it myself, so there's probably something I'm missing. Were your miners able to climb back out again?
(0005387)
Malicus   
2010-04-27 13:46   
Yup. They were idling at the wagon, then they went down the down stairs on the surface, the constructed up/down stairs, and arrived at the up stairs below them, then they mined out the area and went back to the wagon.
(0005512)
hyndis   
2010-04-28 06:03   
I haven't seen this. I almost always replace my natural carved stairways with block stairways for aesthetic reasons by just building the up or down stairway on top of the block stairway, and no pathing issues having.

Is this up/down stairs you are building? Up stairs? Or down stairs? Those are 3 different things. Up stairs and down stairs work fine for me when being built over natural carved up stairs or down stairs.
(0005521)
ercdvs   
2010-04-28 06:58   
Hmm I wonder if i came across this myself. I have a 3x3 block of up/down stairs, with a channel in the middle. I mistakenly removed one corner to be just a 'down' stair. I then rebuild a proper up/down stair on top of it.

I had constant messages of 'could not find path' as dwarves came up specifically using that corner. so much so they just sat there and died of starvation,etc.
(0005542)
Footkerchief   
2010-04-28 09:24   
ercdvs: does that behavior persist through a save/load? If so, you should definitely upload the save. http://dffd.wimbli.com/ [^]
(0005545)
DoctorZuber   
2010-04-28 09:30   
(edited on: 2010-04-28 09:34)
this behavior is consistent with 40d, I saw it a lot since I like to use ramp digging to make large areas and in the process of removing the leftover ramps I'd occasionally hit my staircase which changed an up/down staircase into a down staircase breaking a path.

Trying to fix this, naturally I placed a constructed up/down staircase on it, which doesn't work.

Trying more, I removed this, channeled out the old staircases, and replaced them with constructed stairs. I always use multiple staircases to have a wider path, so I just did half the stair, than the other half until the matter was all fixed.

After accidentally breaking pathing in my fortress a few times I got in the habit of always replacing any key staircases with constructions so that I couldn't accidentally kill them with ramp removal jobs.

Simply put, constructed stairs must be placed on a empty floor, or on open space. Not on top of a pre-existing down staircase.
(0005551)
DoctorZuber   
2010-04-28 10:35   
okay now that's just weird. I figured I ought to quickly verify what I just said, and oddly enough, I couldn't reproduce this. I've seen it dozens of times in 40d, and yet now when I try to recreate it in a controlled manner, it's not cooperating.

Weird.