0008907: Multiple incorrect "cancels Construct Building: Cannot reach site."

Notes
(0032520) m-logik (reporter) 2015-04-05 19:06	http://dffd.bay12games.com/file.php?id=10734 [^] This save is centered on the area in question. One shop is already built and two of the shops are suspended, with another to be suspended shortly after unpausing.

(0032521) Afghani84 (reporter) 2015-04-05 19:06	Hmm...did you check for burrows? Apart from that...one of the workshops might be cluttered and impede movement that way. Would be good if you had a save to check what exactly is going on!

(0032522) m-logik (reporter) 2015-04-05 19:31	@ Afghani84: the save is already provided in the comment above yours. The entire area is a part of the only burrow that has been made on the map, to which no dwarves are currently assigned. The only shop that was successfully built has never been used yet, and cluttered workshops don't impede passability anyway, as far as I'm aware.

(0032526) m-logik (reporter) 2015-04-05 22:03	An update: it appears that unsuspending the shops in order from outside-in allows them to be built two at a time. i.e. In a row of 10 shops set to be built, the first and tenth can built, then the second and ninth, etc. This is even more confusing, as the impassable tiles in a completed mason's shop reduce the number of paths to each building.

(0032552) m-logik (reporter) 2015-04-08 18:27	Here it is again, this time along the southern wall of the same room. http://dffd.bay12games.com/file.php?id=10744 [^] In this instance, there are a variety of shops set to be built in the same configuration as before. As before, the outermost shops will be constructed and all others will be suspended, unsuspending them in outside-in order as each successive shop is built allows them to all be built eventually. In the save provided, the very first build cancellation of this series has just occurred. The dwarf that was constructing the building that was suspended is actually standing in the shop that he was unable to path to. If you allow it to run, 7 more cancellations will follow, with dwarves moving through the supposedly inaccessible shops the entire time.

(0034510) m-logik (reporter) 2016-01-22 00:15	Still occurs in .42.04 and .42.05. I'm pretty sure I've figured out what causes this. When multiple buildings are set to be constructed adjacent to one another, if building one would require a dwarf to move material onto a tile occupied by a not-yet-constructed building, the job suspends with the erroneous cancellation. In the example above, this is why the outermost buildings were able to complete; there were always adjacent tiles without unfinished buildings occupying them that dwarves could move boulders into. Any easy way to replicate this is dig a 1-wide corridor and designate a few tiles in it as a stockpile for a plentiful item like stone. When the tiles are filled, delete the stockpile and try to build 3 doors adjacent to one another on those tiles. Assuming enough idle dwarves to try to build all 3 doors simultaneously, the center door will be suspended with "cannot reach site" cancellation message, because the dwarf cannot move the stone into an adjacent tile. The same can be observed in a 3-wide corridor with any workshops, but if you try to replicate it that way be sure you don't set them to be built with materials on the tiles where they're being built, or you may see a different, correct cancellation (item blocking site) due to the materials they want to move being tasked for another job. In any of these cases, once the outer buildings are completed the dwarves will freely move material onto them to construct the inner buildings. Whether or not the cancellation and suspension is a bug isn't obvious, but the cancellation message itself is misleading and probably not intended.

(0034513) Loci (manager) 2016-01-22 12:28	Related to 0008879; same erroneous error message and apparently the blocking items cannot be moved diagonally.

Issue History
Date Modified	Username	Field	Change
2015-04-05 18:57	m-logik	New Issue
2015-04-05 19:06	m-logik	Note Added: 0032520
2015-04-05 19:06	Afghani84	Note Added: 0032521
2015-04-05 19:31	m-logik	Note Added: 0032522
2015-04-05 22:03	m-logik	Note Added: 0032526
2015-04-08 18:27	m-logik	Note Added: 0032552
2016-01-22 00:15	m-logik	Note Added: 0034510
2016-01-22 12:28	Loci	Note Added: 0034513
2016-07-07 07:12	Loci	Relationship added	related to 0008879