Use importorskip for PIL in ReAct test (#8870)

Author: TomeHirata

pyproject.toml

@@ -40,6 +40,7 @@ dependencies = [
     "cachetools>=5.5.0",
     "cloudpickle>=3.0.0",
     "rich>=13.7.1",
+    "pillow>=10.1.0",
     "numpy>=1.26.0",
     "xxhash>=3.5.0",
     "gepa[dspy]==0.0.17",

tests/predict/test_react.py

@@ -2,14 +2,17 @@
 
 import litellm
 import pytest
-from PIL import Image
 from pydantic import BaseModel
 
 import dspy
 from dspy.utils.dummies import DummyLM
 
 
+@pytest.mark.extra
 def test_tool_observation_preserves_custom_type():
+    pytest.importorskip("PIL.Image")
+    from PIL import Image
+
     captured_calls = []
 
     class SpyChatAdapter(dspy.ChatAdapter):