Release v2.5.20: expanded attention backends (FA2/FA3/SA2/SA3), macOS MPS dtype fixes, bitsandbytes ROCm shim, flash-attn DLL fallback

Author: adrientoupet

README.md

@@ -36,6 +36,15 @@ We're actively working on improvements and new features. To stay informed:
 
 ## 🚀 Release Notes
 
+**2025.12.12 - Version 2.5.20**
+
+- **⚡ Expanded attention backends** - Full support for Flash Attention 2 (Ampere+), Flash Attention 3 (Hopper+), SageAttention 2, and SageAttention 3 (Blackwell/RTX 50xx), with automatic fallback chains to PyTorch SDPA when unavailable *(based on PR by [@naxci1](https://github.com/naxci1) - thank you!)*
+- **🍎 macOS/Apple Silicon compatibility** - Replaced MPS autocast with explicit dtype conversion throughout VAE and DiT pipelines, resolving hangs and crashes on M-series Macs. BlockSwap now auto-disables with warning (unified memory makes it meaningless)
+- **🛡️ Flash Attention graceful fallback** - Added compatibility shims for corrupted or partially installed flash_attn/xformers DLLs, preventing startup crashes
+- **🛡️ AMD ROCm: bitsandbytes conflict fix** - Prevent kernel registration errors when diffusers attempts to re-import broken bitsandbytes installations
+- **📦 ComfyUI Manager: macOS classifier fix** - Removed NVIDIA CUDA classifier causing false "GPU not supported" warnings on macOS
+- **📚 Documentation updates** - Updated README with attention backend details, BlockSwap macOS notes, and clarified model caching descriptions
+
 **2025.12.10 - Version 2.5.19**
 
 - **🎨 New header logo design** - Refreshed ASCII art banner *(thanks [@naxci1](https://github.com/naxci1))*

pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "seedvr2_videoupscaler"
 description = "SeedVR2 official ComfyUI integration: ByteDance-Seed's one-step diffusion-based video/image upscaling with memory-efficient inference"
-version = "2.5.19"
+version = "2.5.20"
 authors = [
     {name = "numz"},
     {name = "adrientoupet"}

src/utils/constants.py

@@ -4,7 +4,7 @@
 """
 
 # Version information
-__version__ = "2.5.19"
+__version__ = "2.5.20"
 
 import os
 import warnings