Not sure what's happened here, but it looks like the noise spiked a bit and kickstarted the CliffCalculator:

I saw something like this once. It seemed to have been a rounding error caused by a noise with a wavelength close to a chunk multiple.

I made a change to hills() which should fix this instance but I don't know if it will fix the overall problem. It's quite rare. Unfortunately this will cause detail changes although not character changes to all sorts of biomes.

Personally, I think it looks pretty cool, but just wanted to post it in case it was a sign of an underlying issue. If it's that rare (and the hills tweak might fix it anyway), I think we can probably close this one. But I'll leave it open for now if you want to look into it.

It's not cool, trust me. It looks hideous in-game. I'm actually less sure about the cause because this came up with the fix I'd done for the time I ran into it before. The current change is almost throwing spaghetti against the wall to see if it sticks, but it's a good change in general (making 2 different noises use different octaves).

Because it's dependent on some rare confluence of events (I know that even if I don't know the events), basically any change should fix that particular incidence.

Closing this as it's likely been fixed in 0.8.0-snapshot-3 but we can always re-open if it appears again.