The Bug:

Igloo basements can generate exposed to the air.

The generation of an igloo's basement can occasionally dip into some natural cave generation, causing it to be extremely obvious when it's instead supposed to be hidden from the player.

Here is an example:

Seed: -2055074493936140863
Coordinates: /execute in minecraft:overworld run tp @s -19683.79 88.00 -862.70 -58.42 14.69

Steps to Reproduce:

1. Generate a world with the seed provided above and teleport to the given coordinates.
2. Look closely at the igloo basement.
3. Take note as to whether or not igloo basements can generate exposed to the air.

Observed Behavior:

Igloo basements can generate exposed to the air.

Expected Behavior:

Igloo basements would not be able to generate exposed to the air.