Background
I had an idea: To reduce the number of mines in a minefield by placing smaller, isolated clusters of mines and using walls/pipes to direct enemies into them.Something like this, or so I hoped:
Land Mine Funnel
But while testing designs, I kept having inconsistent attacks on the walls/pipes and eventually discovered the cause: a show-stopper bug in unit group (biter wave) behavior.
Video
https://www.youtube.com/watch?v=-gpXNn_Ol5kNormal Behavior
See 0:50 timestamp.When a unit group is following a path and there are no targetable military units or structures nearby to trigger aggro (buried land mines are not targetable), the unit group just walks into land mines without reacting to them.
Bugged Behavior
See 0:00 and 1:15 timestamps.When a unit group's "Distance to goal" (show-debug-info-in-tooltips) is greater than ~160 tiles, every time a unit hits a land mine, the unit group's state is incorrectly set to "Arrived", which causes the group to attack player-owned non-military entities like walls/pipes.
Even if no targetable player entities are nearby, the whole unit group is still pseudo-stunned every time a mine detonates, because the group takes several ticks to cycle through a few different different behavior states before returning to FollowPath.
The group also makes strange calls to the pathfinder, generating paths to nonsense locations for no reason, and not using those paths.
Savegame attached