ignore dynamic version in setup.cfg

partial solution to #1216

Author: RonnyPfannschmidt

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Changelog
 
+
+## v9.2.0
+
+### fixed
+
+- fix #1216: accept and create a warning for usages of `version = attr:` in setuptools config.
+  unfortunately dozens of projects cargo-culted that antipattern
+
+
 ## v9.2.0
 
 ### Added

src/setuptools_scm/_integration/setup_cfg.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import os
+import warnings
 
 from dataclasses import dataclass
 from pathlib import Path
@@ -25,6 +26,12 @@ def read_setup_cfg(input: str | os.PathLike[str] = "setup.cfg") -> SetuptoolsBas
 
     name = parser.get("metadata", "name", fallback=None)
     version = parser.get("metadata", "version", fallback=None)
+    if version is not None and "attr" in version:
+        warnings.warn(
+            "setup.cfg: ignoring invalid dynamic version - version = attr: ..."
+            " is sabotaging setuptools-scm"
+        )
+        version = None
     return SetuptoolsBasicData(path=path, name=name, version=version)
 
 

testing/test_integration.py

@@ -18,6 +18,7 @@
 from setuptools_scm._integration import setuptools as setuptools_integration
 from setuptools_scm._integration.pyproject_reading import PyProjectData
 from setuptools_scm._integration.setup_cfg import SetuptoolsBasicData
+from setuptools_scm._integration.setup_cfg import read_setup_cfg
 from setuptools_scm._requirement_cls import extract_package_name
 
 if TYPE_CHECKING:
@@ -457,6 +458,29 @@ def test_unicode_in_setup_cfg(tmp_path: Path) -> None:
     assert data.version == "1.2.3"
 
 
+@pytest.mark.issue(1216)
+def test_setup_cfg_dynamic_version_warns_and_ignores(tmp_path: Path) -> None:
+    cfg = tmp_path / "setup.cfg"
+    cfg.write_text(
+        textwrap.dedent(
+            """
+            [metadata]
+            name = example-broken
+            version = attr: example_broken.__version__
+            """
+        ),
+        encoding="utf-8",
+    )
+
+    with pytest.warns(
+        UserWarning,
+        match="setup.cfg: ignoring invalid dynamic version - version = attr: ... is sabotaging setuptools-scm",
+    ):
+        legacy_data = read_setup_cfg(cfg)
+
+    assert legacy_data.version is None
+
+
 def test_setup_cfg_version_prevents_inference_version_keyword(
     tmp_path: Path, monkeypatch: pytest.MonkeyPatch
 ) -> None: