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0010815Dwarf FortressMiscellaneous Crashespublic2018-07-06 10:162018-07-07 09:46
Windows10, 64 bit
0010815: game hangs/freezes after forbidding doors separating fort from surface
I have two doors immediately behind two raising bridges which separate my fort from surface access. I marked the doors "forbidden" to make sure nobody wandered through because I was about to pull the lever to raise the bridges, but if I unpause while the doors are forbidden, the game freezes ("not responding", maxed CPU usage on one core) within a second or two.
In this particular case, just load the save (I'll upload and link it momentarily), unpause, and it freezes almost immediately. Then reload, unforbid the two surface doors (south of the trade depot, -2z from the surface), and it will not freeze.

In general, I don't know; I've forbidden these kinds of surface doors plenty of times before in this and other forts' histories with no issue.
I generated the world and played the fort entirely in 0.44.09 using PeridexisErrant's Starter Pack 0.44.09-r01 including DFHack and TWBT, but if I copy the save into the latest 0.44.11 (with no mods) it exhibits exactly the same freeze.

Because it's triggered by forbidding doors I assume it must somehow be related to pathfinding, but I don't know why it would be a problem for this fort at this moment and not any of the other times I've forbidden the same doors. All my dwarves are currently "inside" the doors and there are no pending jobs for items or animals "outside" so I don't think anyone is currently trying to path through them. I suppose a cat could be trying to get out, or a stealthed attacker could be trying to get in, but I don't know how to check for those things.
No tags attached.
duplicate of 0010201acknowledged lethosor Locking door causes game to hang 
Issue History
2018-07-06 10:16taledenNew Issue
2018-07-06 10:19taledenNote Added: 0038548
2018-07-06 10:19taledenIssue Monitored: taleden
2018-07-06 11:33FantasticDorfNote Added: 0038549
2018-07-06 12:11taledenNote Added: 0038550
2018-07-06 12:38taledenNote Added: 0038551
2018-07-07 09:46LociRelationship addedduplicate of 0010201
2018-07-07 09:46LociStatusnew => resolved
2018-07-07 09:46LociResolutionopen => duplicate
2018-07-07 09:46LociAssigned To => Loci

2018-07-06 10:19   
Save file to reproduce: http://dffd.bay12games.com/file.php?id=13870 [^]
2018-07-06 11:33   
Without diving into the save-file directly, at face value this sounds like 0000797, id recommend you keep any free animals you have inside cages and pastures to discourage them trying to path through doors between meeting zones by themselves.
2018-07-06 12:11   
I don't think this is the same issue because it's not just "lag" reducing FPS, it's a complete permanent freeze of the game. Also the doors were already "tightly closed" without causing this issue (I have 4 cats that would sometimes get stuck with the "?" trying to path through it until a dwarf came along, but that had no noticeable impact on FPS); it's only when changing to "forbidden" that this freeze arises.

Also, I've done some more experimentation so far and leaving the doors un-forbidden but pulling the lever to raise the bridges beside them causes exactly the same freeze, just a little later (because the bridges are slower to raise). Next I'll try building constructed walls to seal surface access and see if that also does it, but so far it looks like anything that prevents pathing from inside to outside at this moment in the fort's history (not just forbidden doors) will cause this freeze.
2018-07-06 12:38   
Another clue: I currently have four layers of access control between the surface and my fortress interior: a "main outer gate", a "depot outer gate", a pair of "depot inner gates" (all of those are bridges) and finally the pair of regular doors. Raising/forbidding any of those cuts off pathing to the surface.

However, raising the "main outer gate" does not seem to trigger the freeze, while raising either of the "depot gates" or forbidding the doors does cause the freeze as soon as it takes effect (immediate for the doors, after 100 ticks for the bridges).

The only things between the "main outer gate" and the "depot outer gate" are a pair of war dogs restrained on built ropes, a loose rope lying on the ground, and a refuse stockpile (which takes from anywhere and gives to another refuse stockpile up on the surface).

There are no pending jobs involving any of those things, but it seems that cutting them off from the rest of the fort is what causes the freeze, while cutting them and the fort off from the surface is not a problem.