Add conditional ignore for build and dist dirname

Fix pytest-dev#12625

changelog/12625.improvement.rst

@@ -0,0 +1,2 @@
+Conditionally ignore collection of setuptools artifacts dirnames only if the
+directories reside inside a setuptools project, i.e. `setup.cfg`, is present, etc.

src/_pytest/main.py

@@ -365,6 +365,15 @@ def pytest_runtestloop(session: Session) -> bool:
     return True
 
 
+def _is_setuptools_project(path: Path) -> bool:
+    """Attempt to detect if ``path`` is the root of a setuptools project by
+    checking the existence of setup.py, setup.cfg, or pyproject.toml.
+
+    """
+    indicators = ("setup.py", "setup.cfg", "pyproject.toml")
+    return any((path / f).exists() for f in indicators)
+
+
 def _in_venv(path: Path) -> bool:
     """Attempt to detect if ``path`` is the root of a Virtual Environment by
     checking for the existence of the pyvenv.cfg file.
@@ -421,6 +430,10 @@ def pytest_ignore_collect(collection_path: Path, config: Config) -> bool | None:
         if any(fnmatch_ex(pat, collection_path) for pat in norecursepatterns):
             return True
 
+        if any(fnmatch_ex(pat, collection_path) for pat in ("build", "dist")):
+            if _is_setuptools_project(collection_path.parent):
+                return True
+
     return None
 
 

testing/test_collection.py

@@ -135,7 +135,7 @@ def test_foo():
 
 
 class TestCollectFS:
-    def test_build_conditional_ignore(self, pytester: Pytester) -> None:
+    def test_build_dirs_collected(self, pytester: Pytester) -> None:
         tmp_path = pytester.path
         ensure_file(tmp_path / "build" / "test_found.py")
         ensure_file(tmp_path / "dist" / "test_found.py")
@@ -146,6 +146,32 @@ def test_build_conditional_ignore(self, pytester: Pytester) -> None:
         s = result.stdout.str()
         assert "test_found" in s
 
+    def test_setuptools_ignored_if_present(self, pytester: Pytester) -> None:
+        tmp_path = pytester.path
+        ensure_file(tmp_path / "build" / "test_notfound.py")
+        ensure_file(tmp_path / "dist" / "test_notfound.py")
+        for x in tmp_path.rglob("test_*.py"):
+            x.write_text("def test_hello(): pass", encoding="utf-8")
+
+        ensure_file(tmp_path / "setup.py")
+
+        result = pytester.runpytest("--collect-only")
+        s = result.stdout.str()
+        assert "test_notfound" not in s
+
+    def test_setuptools_ignored_pyproject_toml(self, pytester: Pytester) -> None:
+        tmp_path = pytester.path
+        ensure_file(tmp_path / "build" / "test_notfound.py")
+        ensure_file(tmp_path / "dist" / "test_notfound.py")
+        for x in tmp_path.rglob("test_*.py"):
+            x.write_text("def test_hello(): pass", encoding="utf-8")
+
+        ensure_file(tmp_path / "pyproject.toml")
+
+        result = pytester.runpytest("--collect-only")
+        s = result.stdout.str()
+        assert "test_notfound" not in s
+
     def test_ignored_certain_directories(self, pytester: Pytester) -> None:
         tmp_path = pytester.path
         ensure_file(tmp_path / "_darcs" / "test_notfound.py")