It looks like you can call the frameRate setter anyway, but it has no effect. arView.__enableAutomaticFrameRate = false arView.__preferredFrameRate = 60

This is so needed. I'm a bit bummed that this was not included as an improvement this year, especially since Apple seems to position RealityKit as a rendering framework for macOS-oriented use cases. @gchiste Filed FB11305740

[snip] See reply

Also seeing this issue. I was getting these two errors in different projects: Nothing in the project was calling NSApplication.shared, and building/running the app worked fine... I started removing every single linked framework and source file except one, and made a simple Preview containing a Color.red, and now my Preview won't even load at all:

I'm seeing this issue despite removing all custom build scripts Removing "objective-c++" from MODULE_VERIFIER_SUPPORTED_LANGUAGES in each framework made it much faster (44s -> 14s) But it looks like the verification is still happening each time, it's just faster. I disabled it for the frameworks and gained another 0.5s of build time back.