What happened?

BCLib interferes with biome decoration by inconsistently rotating the generator seed passed to WorldgenRandom.setFeatureSeed(). This may result in potentially unwanted behaviour by changing decorator indexes based on factors such as neighboring biomes in different chunks.

This is identifiable in regular gameplay by the very subtle chunk seams it can cause; and is generally undesirable from a technical perspective as well.

BCLib

21.0.13

WorldWeaver

21.0.13

Fabric API

0.115.1

Fabric Loader

1.16.10

Minecraft

1.21

Relevant log output

N/A

Other Mods

fabric-api-0.115.1+1.21.1
worldweaver-21.0.13
bclib-21.0.13
betternether/betterend NOT installed

If I may add, this mod has always done wacky things with world generation, I don't know why it needs to be done like this. BetterNether and End could probably just rely on Terrablender, which has way less stuff going on in its code. (And if you want features that don't exist, you can always just submit pull requests, not hard.)