Revert setuptools pin as k-diffusion pipelines are now deprecated

.github/workflows/pr_tests_gpu.yml

@@ -199,11 +199,6 @@ jobs:
 
     - name: Install dependencies
       run: |
-        # Install pkgs which depend on setuptools<81 for pkg_resources first with no build isolation
-        uv pip install pip==25.2 setuptools==80.10.2
-        uv pip install --no-build-isolation k-diffusion==0.0.12
-        uv pip install --upgrade pip setuptools
-        # Install the rest as normal
         uv pip install -e ".[quality]"
         uv pip install peft@git+https://github.com/huggingface/peft.git
         uv pip uninstall accelerate && uv pip install -U accelerate@git+https://github.com/huggingface/accelerate.git

.github/workflows/push_tests.yml

@@ -126,11 +126,6 @@ jobs:
 
     - name: Install dependencies
       run: |
-        # Install pkgs which depend on setuptools<81 for pkg_resources first with no build isolation
-        uv pip install pip==25.2 setuptools==80.10.2
-        uv pip install --no-build-isolation k-diffusion==0.0.12
-        uv pip install --upgrade pip setuptools
-        # Install the rest as normal
         uv pip install -e ".[quality]"
         uv pip install peft@git+https://github.com/huggingface/peft.git
         uv pip uninstall accelerate && uv pip install -U accelerate@git+https://github.com/huggingface/accelerate.git

src/diffusers/pipelines/prx/pipeline_prx.py

@@ -18,6 +18,7 @@ import re
 import urllib.parse as ul
 from typing import Callable
 
+import ftfy
 import torch
 from transformers import (
     AutoTokenizer,
@@ -33,13 +34,13 @@ from diffusers.models.transformers.transformer_prx import PRXTransformer2DModel
 from diffusers.pipelines.pipeline_utils import DiffusionPipeline
 from diffusers.pipelines.prx.pipeline_output import PRXPipelineOutput
 from diffusers.schedulers import FlowMatchEulerDiscreteScheduler
-from diffusers.utils import is_ftfy_available, logging, replace_example_docstring
+from diffusers.utils import (
+    logging,
+    replace_example_docstring,
+)
 from diffusers.utils.torch_utils import randn_tensor
 
 
-if is_ftfy_available():
-    import ftfy
-
 DEFAULT_RESOLUTION = 512
 
 ASPECT_RATIO_256_BIN = {

tests/pipelines/prx/test_pipeline_prx.py

@@ -1,6 +1,7 @@
 import unittest
 
 import numpy as np
+import pytest
 import torch
 from transformers import AutoTokenizer
 from transformers.models.t5gemma.configuration_t5gemma import T5GemmaConfig, T5GemmaModuleConfig
@@ -10,11 +11,17 @@ from diffusers.models import AutoencoderDC, AutoencoderKL
 from diffusers.models.transformers.transformer_prx import PRXTransformer2DModel
 from diffusers.pipelines.prx.pipeline_prx import PRXPipeline
 from diffusers.schedulers import FlowMatchEulerDiscreteScheduler
+from diffusers.utils import is_transformers_version
 
 from ..pipeline_params import TEXT_TO_IMAGE_PARAMS
 from ..test_pipelines_common import PipelineTesterMixin
 
 
+@pytest.mark.xfail(
+    condition=is_transformers_version(">", "4.57.1"),
+    reason="See https://github.com/huggingface/diffusers/pull/12456#issuecomment-3424228544",
+    strict=False,
+)
 class PRXPipelineFastTests(PipelineTesterMixin, unittest.TestCase):
     pipeline_class = PRXPipeline
     params = TEXT_TO_IMAGE_PARAMS - {"cross_attention_kwargs"}