Dwarf cancels Construct Building: Item blocking site

xTATTEREDx  · +FINE+  · *SUPERIOR*  · ≡EXCEPTIONAL≡  · ☼MASTERWORK☼

v50.12 · v0.47.05 This article is about the current version of DF. Note that some content may still need to be updated. More Info · V

This occurs when a dwarf is trying to clear the tile(s) of a building site and there is an item which the dwarf is not allowed to pick up lying on the ground where you want to place the building.

For instance...

• ... the item is forbidden.
• ... the item is marked for dumping.
• ... the item is tasked to be used in a different building.
• ... the item is tasked to be hauled to a stockpile.
• ... the item is tasked to be hauled to the trade depot.
• ... the item is tasked to be used in a workshop.

One of the more common situations is when you have a field of mined stones, and you have designated several workshops and/or walls to be built there using some of those same stones. "Workshop A" gets canceled because "Wall B's" stone is in the way, and vice versa - neither can be built since the other's stone can't be moved.

Or, same situation, but several masons are actively using up those stones, or there's a stone stockpile the stones are going to, or you've marked them for dumping - if one mason or hauler is walking toward a stone when it needs to be cleared from the workshop area, it's "tasked" for something else - and can't be moved.

If the item is tasked for something, it will probably (read "hopefully") be taken away very quickly as that job is handled; you can often just un-suspend the construction and it will complete with no further error. Forbidden items, however, will have to be manually unforbidden in order to make construction possible.

In extreme cases, try the following steps:

1. pause the game, via spacebar.
2. forbid any and all items that might possibly be blocking the building. (This can be done via k, then f, or, for larger areas, via d, b, f and then either using Enter to designate a large area or left-clicking with the mouse.) This will cancel any tasks associated with all items.
3. unforbid them again.
4. remove the workshop/building job, via q, x.
5. re-designate the same workshop/building job - or a few less than you had before, if several might be overlapping. This is to prioritize that building for your (now idle?) construction dwarves.
6. and, if it's not obvious, then unpause the game, via spacebar.

In very rare cases, the worst culprit is a piece of clothing that a dwarf has discarded while changing into armour. That personal item may be permanently tasked for retrieval, yet due to a known game glitch the dwarf will never retrieve it. In such cases, alternating the dwarf in question between armour levels, from "clothing" to "leather" to "plate" and back, repeatedly, may (eventually) shake them out of it and they'll grab their sock, or whatever has brought construction to a magma-gargling halt. For particularly stubborn cases, DFHack provides several commands that can clear things up: "cleanowned scattered" will confiscate owned items that were abandoned by your dwarves (allowing them to be stockpiled or dumped), and "autodump destroy-here" simply eliminates items under the cursor.