The bug
Witch huts generated by new world generator doesn't spawn witches. Only one pregenerated witch is spawned.
How to reproduce
Example I
Seed & coordinates:
-9144014475768710727
/teleport @s -220 69 20
make some floors and big roof in place of witch hut, after that run several times:
/kill @e[type=!player,type=!witch]
Watch what spawns at the witch hut location.
Example II
Seed & coordinates:
ILoveMojang
/teleport @s 825 68 -863 200 0
Preparation for best conditions:
/fill 832 64 -888 838 71 -896 minecraft:air
/fill 822 73 -868 858 73 -916 minecraft:stone_slab
/fill 832 69 -888 838 69 -896 minecraft:acacia_bark
/fill 832 66 -888 838 66 -896 minecraft:acacia_bark
/fill 832 63 -888 838 63 -896 minecraft:acacia_bark
then repeat:
/kill @e[type=!player,type=!witch]
Related issues
relates to
Comments


Note to self:
TODO: Check if witch hut worked in previous snapshot - to be sure that witch hut broke in this snapshot.
TODO2: Check if old witch hut (generated in 1.12.2) works in this snapshot. -> Confirmed by Unarybit
Can't check this for a while.

Also, witches do not spawn in witch huts from the "old" world generator before 18w06a.

seems to be fixed in 18w09a - witch hut generated in this snapshot is working as expected.
The structure bounding box is apparently correctly saved, but due to the changes to world generation and the new region chunk data structure it is hard to tell if anything else there is wrong.