huggingface / huggingface/diffusers
Incompatibility between FlashAttention and ERNIE-Image
Open
Nobody has claimed this yet.
bug
pipelines
- Dominant language
- Python
- Stars
- 34.5k
- Forks
- 7.3k
- Avg merge
- 3d 3h
- Merged PRs (30d)
- 91
Description
Hello,
When I enable FlashAttention backend on an ErnieImagePipeline, it crashes with following error:
ValueError: attn_mask is not supported for flash-attn 2.
But same Python code (see below) doesn't crash with ZImagePipeline and Flux2KleinPipeline.
Reproduction
pipeline.transformer.set_attention_backend("flash")
System Info
- OS: Windows
- Python: 3.13.11
- Diffusers: 9c4e201dd1cf7d16449c3f4e9affc556d7bc3404
- FlashAttention: 2.8.3+cu130torch2.10
- SDNQ: 0.1.6
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with ErnieImagePipeline and its transformer attention setup, then compare attention-mask handling with ZImagePipeline and Flux2KleinPipeline. Reproduce the shown set_attention_backend("flash") failure in the stated environment; done means ERNIE-Image can use the flash backend without the attn_mask error.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python, pytorch
- Domain
- machine-learning
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Quiet
- Clarity
- Mostly clear
- Newbie friendliness
- 55/100