|Description||I was trying to get my dwarves digging to "glory" ASAP, so I had them drill two holes in the mountainside leading to 1x2 up/down staircases, and designated staircases for several z-levels. These mountainside tunnels both led to ONE (the rightmost) staircase. The dwarf tunneling from the south tunneled out the first staircase, and queued up for the staircase diagonally (northwest) from him. At the same time, the dwarf in the eastern tunnel breached the east side of the staircase the other dwarf just finished, and queued up the staircase BELOW the staircase that was just finished.|
Apparently, the south dwarf was attempting to path to the square with the staircase he just finished in order to dig out the staircase northwest of him. The other dwarf wanted the same square to dig out the staircase one z-level below. I COULD assume that they were both being extra-modest in an infinite loop of "No, I can wait, YOU take the square first".
I was forced to disable the mining labor on the east dwarf. He canceled his mining job (I thought they finished their job before quitting the labor?) and the southern dwarf took the square they were fighting over, and finished the staircase. Re-enabling the labor on the east dwarf cause digging to proceed normally.
Since pathing isn't really plannable in any way down to the last second, this is fairly minor and shouldn't happen often, if at all, and an uncommon situation, but if not caught by the administrator (i.e. the player), it can cause the dwarves to basically brainfreeze until they cancel their job for something else like food or drink. If that doesn't happen, they'll eventually die.