Fix LayerSkipConfig shorthand crash in SkipLayerGuidance and AutoGuidance

src/diffusers/guiders/auto_guidance.py

@@ -104,7 +104,7 @@ def __init__(
                     f"Expected `auto_guidance_layers` to be an int or a list of ints, but got {type(auto_guidance_layers)}."
                 )
             auto_guidance_config = [
-                LayerSkipConfig(layer, fqn="auto", dropout=dropout) for layer in auto_guidance_layers
+                LayerSkipConfig(indices=[layer], fqn="auto", dropout=dropout) for layer in auto_guidance_layers
             ]
 
         if isinstance(auto_guidance_config, dict):

src/diffusers/guiders/skip_layer_guidance.py

@@ -136,7 +136,7 @@ def __init__(
                 raise ValueError(
                     f"Expected `skip_layer_guidance_layers` to be an int or a list of ints, but got {type(skip_layer_guidance_layers)}."
                 )
-            skip_layer_config = [LayerSkipConfig(layer, fqn="auto") for layer in skip_layer_guidance_layers]
+            skip_layer_config = [LayerSkipConfig(indices=[layer], fqn="auto") for layer in skip_layer_guidance_layers]
 
         if isinstance(skip_layer_config, dict):
             skip_layer_config = LayerSkipConfig.from_dict(skip_layer_config)

tests/guiders/test_skip_layer_guidance.py

@@ -0,0 +1,40 @@
+# Copyright 2025 HuggingFace Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from diffusers.guiders.auto_guidance import AutoGuidance
+from diffusers.guiders.skip_layer_guidance import SkipLayerGuidance
+
+
+class TestSkipLayerGuidanceConfig:
+    def test_skip_layer_guidance_layers_shorthand_builds_list_indices(self):
+        guider = SkipLayerGuidance(
+            guidance_scale=7.0,
+            skip_layer_guidance_layers=[7, 8, 9],
+            skip_layer_guidance_scale=2.8,
+        )
+
+        assert [config.indices for config in guider.skip_layer_config] == [[7], [8], [9]]
+        for config in guider.skip_layer_config:
+            assert 7 in config.indices or 8 in config.indices or 9 in config.indices
+
+    def test_auto_guidance_layers_shorthand_builds_list_indices(self):
+        guider = AutoGuidance(
+            guidance_scale=7.0,
+            auto_guidance_layers=[3, 4],
+            dropout=1.0,
+        )
+
+        assert [config.indices for config in guider.auto_guidance_config] == [[3], [4]]
+        for config in guider.auto_guidance_config:
+            assert config.indices[0] in config.indices

utils/check_copies.py

@@ -18,6 +18,7 @@
 import os
 import re
 import subprocess
+import sys
 
 
 # All paths are set with the intent you should run this script from the root of the repo with the command
@@ -94,7 +95,7 @@ def get_indent(code):
 
 
 def run_ruff(code):
-    command = ["ruff", "format", "-", "--config", "pyproject.toml", "--silent"]
+    command = [sys.executable, "-m", "ruff", "format", "-", "--config", "pyproject.toml", "--silent"]
     process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
     stdout, _ = process.communicate(input=code.encode())
     return stdout.decode()