fix: pin pillow to exclude broken 12.3.0 release

pyproject.toml

@@ -24,7 +24,7 @@ dependencies = [
     "ollama>=0.5.1",
     "requests>=2.32.3",
     "mistletoe>=1.4.0",
-    "pillow>=12.0.0", # Needed for Intrinsics (HF and OpenAI Backends).
+    "pillow>=12.2.0,!=12.3.0", # Needed for Intrinsics (HF and OpenAI Backends). 12.3.0 removed PIL._typing._Ink, breaking docling (issue#1640).
     "math_verify", # Needed for Majority Voting Sampling Strategies.
     "nltk>=3.9,!=3.10.1", # Needed for sentence tokenization in granite citation parsing.
     "rouge_score", # Needed for Majority Voting Sampling Strategies.

test/package/test_pillow_constraint.py

@@ -0,0 +1,41 @@
+# Copyright IBM Corp. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+"""Tests that the core `pillow` dependency specifier excludes the broken 12.3.0 release.
+
+Pillow 12.3.0 removed `_Ink` from `PIL._typing`, which breaks `from PIL import
+ImageText` and cascades through `docling_core` into `RichDocument` (issue #1640).
+These tests assert the specifier in `pyproject.toml` cannot resolve 12.3.0 while
+still admitting the known-good releases.
+"""
+
+from __future__ import annotations
+
+import tomllib
+from pathlib import Path
+
+from packaging.requirements import Requirement
+
+PYPROJECT = Path(__file__).resolve().parents[2] / "pyproject.toml"
+
+
+def _pillow_specifier():
+    """Return the `SpecifierSet` for the core `pillow` dependency in pyproject.toml."""
+    with PYPROJECT.open("rb") as f:
+        pyproject = tomllib.load(f)
+    for dep in pyproject["project"]["dependencies"]:
+        req = Requirement(dep)
+        if req.name == "pillow":
+            return req.specifier
+    raise AssertionError("pillow not found in core dependencies")
+
+
+def test_pillow_specifier_excludes_broken_1230():
+    """The pillow specifier must not admit the broken 12.3.0 release (issue #1640)."""
+    assert "12.3.0" not in _pillow_specifier()
+
+
+def test_pillow_specifier_allows_working_versions():
+    """The pillow specifier still admits the known-good 12.2.0 release."""
+    spec = _pillow_specifier()
+    assert "12.2.0" in spec