no longer require tool secrion when the version keyword is used

closes #1194

Author: RonnyPfannschmidt

src/setuptools_scm/_integration/version_inference.py

@@ -154,20 +154,23 @@ def get_version_inference_config(
 
     # Handle missing configuration
     if not pyproject_data.is_required and not pyproject_data.section_present:
-        # If there are overrides, proceed with inference (explicit use_scm_version)
+        # If version_keyword was called (overrides is not None), activate setuptools_scm
+        # This handles both use_scm_version=True (empty {}) and use_scm_version={config}
         if overrides is not None:
             return VersionInferenceConfig(
                 dist_name=dist_name,
                 pyproject_data=pyproject_data,
                 overrides=overrides,
             )
+        # If infer_version was called (overrides is None), only activate with config
         return VersionInferenceNoOp()
 
     # Handle missing project section when required
     if (
         pyproject_data.is_required
         and not pyproject_data.section_present
         and not pyproject_data.project_present
+        and overrides is None  # Only return NoOp for infer_version, not version_keyword
     ):
         return VersionInferenceNoOp()
 

testing/test_integration.py

@@ -1305,3 +1305,38 @@ def test_infer_version_logs_debug_when_missing_dynamic_version(
 
     # Verify that version was not set due to configuration issue
     assert dist.metadata.version is None
+
+
+@pytest.mark.issue("xmlsec-regression")
+def test_xmlsec_download_regression(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    """Test that pip download works for xmlsec package without causing setuptools_scm regression.
+
+    This test ensures that downloading and building xmlsec from source doesn't fail
+    due to setuptools_scm issues when using --no-build-isolation.
+    """
+    # Set up environment with setuptools_scm debug enabled
+    monkeypatch.setenv("SETUPTOOLS_SCM_DEBUG", "1")
+    monkeypatch.setenv("COLUMNS", "150")
+
+    # Run pip download command with no-binary and no-build-isolation
+    try:
+        subprocess.run(
+            [
+                *(sys.executable, "-m", "pip", "download"),
+                *("--no-binary", "xmlsec"),
+                "--no-build-isolation",
+                "-v",
+                "xmlsec==1.3.16",
+            ],
+            cwd=tmp_path,
+            text=True,
+            timeout=300,
+            check=True,
+        )
+    except subprocess.CalledProcessError as e:
+        pytest.fail(f"pip download failed: {e}", pytrace=False)
+
+    # The success of the subprocess.run call above means the regression is fixed.
+    # pip download succeeded without setuptools_scm causing version conflicts.

testing/test_version_inference.py

@@ -81,26 +81,70 @@ def test_no_pyproject_toml(self) -> None:
         # and not call get_version_inference_config at all.
         # This test is no longer needed as pyproject_data is always required.
 
-    def test_no_setuptools_scm_config(self) -> None:
-        """Test that we don't infer when setuptools-scm is not configured."""
+    def test_no_setuptools_scm_config_infer_version(self) -> None:
+        """Test that we don't infer when setuptools-scm is not configured and infer_version called."""
         result = get_version_inference_config(
             dist_name="test_package",
             current_version=None,
             pyproject_data=PyProjectData.for_testing(False, False, True),
+            overrides=None,  # infer_version call
         )
 
         assert isinstance(result, VersionInferenceNoOp)
 
-    def test_setuptools_scm_required_no_project_section(self) -> None:
-        """Test that we don't infer when setuptools-scm is required but no project section."""
+    def test_no_setuptools_scm_config_version_keyword(self) -> None:
+        """Test that we DO infer when setuptools-scm is not configured but use_scm_version=True."""
+        result = get_version_inference_config(
+            dist_name="test_package",
+            current_version=None,
+            pyproject_data=PyProjectData.for_testing(False, False, True),
+            overrides={},  # version_keyword call with use_scm_version=True
+        )
+
+        assert isinstance(result, VersionInferenceConfig)
+        assert result.dist_name == "test_package"
+        assert result.overrides == {}
+
+    def test_setuptools_scm_required_no_project_section_infer_version(self) -> None:
+        """Test that we don't infer when setuptools-scm is required but no project section and infer_version called."""
         result = get_version_inference_config(
             dist_name="test_package",
             current_version=None,
             pyproject_data=PyProjectData.for_testing(True, False, False),
+            overrides=None,  # infer_version call
         )
 
         assert isinstance(result, VersionInferenceNoOp)
 
+    def test_setuptools_scm_required_no_project_section_version_keyword(self) -> None:
+        """Test that we DO infer when setuptools-scm is required but no project section and use_scm_version=True."""
+        result = get_version_inference_config(
+            dist_name="test_package",
+            current_version=None,
+            pyproject_data=PyProjectData.for_testing(True, False, False),
+            overrides={},  # version_keyword call with use_scm_version=True
+        )
+
+        assert isinstance(result, VersionInferenceConfig)
+        assert result.dist_name == "test_package"
+        assert result.overrides == {}
+
+    def test_setuptools_scm_required_no_project_section_version_keyword_with_config(
+        self,
+    ) -> None:
+        """Test that we DO infer when setuptools-scm is required but no project section and use_scm_version={config}."""
+        overrides = {"version_scheme": "calver"}
+        result = get_version_inference_config(
+            dist_name="test_package",
+            current_version=None,
+            pyproject_data=PyProjectData.for_testing(True, False, False),
+            overrides=overrides,  # version_keyword call with use_scm_version={config}
+        )
+
+        assert isinstance(result, VersionInferenceConfig)
+        assert result.dist_name == "test_package"
+        assert result.overrides == overrides
+
     def test_setuptools_scm_required_with_project_section(self) -> None:
         """Test that we infer when setuptools-scm is required and project section exists."""
         result = get_version_inference_config(