Similar experience with a game engine. While working on one isolated component, like the render pipeline, a portion of the backing sparse data buffers were effectively duplicated with a different ABI. It’s like it forgot how to query meshes and game state, then assumed the plumbing didn’t exist so it was all rebuilt from scratch.

It compiled and ran just fine. If you weren’t reviewing the code holistically or keeping tight book keeping of your allocations you would not have noticed. Every single commit in isolation looks perfect. Very eye-opening