WanVACEPipeline does not work with low-noise stage only

[vladmandic]

Describe the bug

WanVACEPipeline has unnecessary/unsafe access to high-noise transformer module of the model which invalidates the ability to use low-noise stage only that was introduced in #12024

diffusers/src/diffusers/pipelines/wan/pipeline_wan_vace.py

Line 339 in b596545

base = self.vae_scale_factor_spatial * self.transformer.config.patch_size[1]

fix is trivial, gather transformer.config.patch_size[1] from either either transformer or transformer_2, whichever is available.

Reproduction

load WanVACEPipeline with low-noise stage only transformer_2 and keep high-noise stage transformer as None.

Logs

│C:\ai\sdnext\venv\Lib\site-packages\diffusers\pipelines\wan\pipeline_wan_vace.py:339 in check_inputs                  │
│                                                                                                                      │
│   338 │   ):                                                                                                         │
│❱  339 │   │   base = self.vae_scale_factor_spatial * self.transformer.config.patch_size[1]                           │
│   340 │   │   if height % base != 0 or width % base != 0:                                                            │
╰──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
AttributeError: 'NoneType' object has no attribute 'config'

System Info

diffusers main branch

Who can help?

@yiyixuxu @sayakpaul @DN6