macOS 27 developer beta can break ComfyUI on a Mac mini
ComfyUI can become unreliable on Macs after installing the . On a with 48GB of memory, ComfyUI crashed partway through . The crash did not happen at one fixed step; it could appear around KSampler, VAE Decode, an upscaler, or another node.
The error points to a failed low-level macOS call that reports memory information. The likely cause is a change in the of macOS that makes the psutil library fail after the first few memory checks inside the same running process. ComfyUI treats even one failed memory reading as a fatal error and stops the job.
A temporary workaround is to add a small shim inside the ComfyUI so ComfyUI gets a cached memory value when the macOS call fails. The title also says the beta can cause noisy or ruined images, but the provided text does not include enough detail about that second issue or its fix.
Key points
- The can make ComfyUI crash on Macs.
- The reported setup was a with 48GB of memory.
- The crash appears during and can happen at different ComfyUI nodes.
- The issue is tied to macOS memory reporting and the psutil library, not necessarily to the image workflow.
- A temporary shim can return a cached memory value when the normal macOS memory call fails.