BUG: Fix warning stacklevel

changelog/12564.bugfix.rst

@@ -0,0 +1 @@
+Fix the ``stacklevel`` used when warning about marks used on fixtures.

src/_pytest/deprecated.py

@@ -11,7 +11,11 @@
 
 from __future__ import annotations
 
+import inspect
+from pathlib import Path
+from typing import Any
 from warnings import warn
+from warnings import warn_explicit
 
 from _pytest.warning_types import PytestDeprecationWarning
 from _pytest.warning_types import PytestRemovedIn9Warning
@@ -89,3 +93,25 @@
 def check_ispytest(ispytest: bool) -> None:
     if not ispytest:
         warn(PRIVATE, stacklevel=3)
+
+
+def _warn_auto_stacklevel(message: Warning | str, category: Any = UserWarning) -> None:
+    """Emit a warning with trace outside the pytest namespace."""
+    root_dir = Path(__file__).parent
+    frame = inspect.currentframe()
+    fname, lineno = "unknown", 0
+    while frame:
+        fname = frame.f_code.co_filename
+        lineno = frame.f_lineno
+        if fname and root_dir not in Path(fname).parents:
+            break
+        frame = frame.f_back
+    del frame
+    warn_explicit(
+        message,
+        category,
+        filename=fname,
+        lineno=lineno,
+        module="pytest",
+        registry=globals().get("__warningregistry__", {}),
+    )

src/_pytest/fixtures.py

@@ -33,7 +33,6 @@
 from typing import TYPE_CHECKING
 from typing import TypeVar
 from typing import Union
-import warnings
 
 import _pytest
 from _pytest import nodes
@@ -57,6 +56,7 @@
 from _pytest.config import Config
 from _pytest.config import ExitCode
 from _pytest.config.argparsing import Parser
+from _pytest.deprecated import _warn_auto_stacklevel
 from _pytest.deprecated import check_ispytest
 from _pytest.deprecated import MARKED_FIXTURE
 from _pytest.deprecated import YIELD_FIXTURE
@@ -1192,7 +1192,7 @@
             )
 
         if hasattr(function, "pytestmark"):
-            warnings.warn(MARKED_FIXTURE, stacklevel=2)
+            _warn_auto_stacklevel(MARKED_FIXTURE)
 
         function = wrap_function_to_error_out_if_called_directly(function, self)
 
@@ -1322,7 +1322,7 @@
     .. deprecated:: 3.0
         Use :py:func:`pytest.fixture` directly instead.
     """
-    warnings.warn(YIELD_FIXTURE, stacklevel=2)
+    _warn_auto_stacklevel(YIELD_FIXTURE)
     return fixture(
         fixture_function,
         *args,

src/_pytest/mark/structures.py

@@ -18,13 +18,13 @@
 from typing import TYPE_CHECKING
 from typing import TypeVar
 from typing import Union
-import warnings
 
 from .._code import getfslineno
 from ..compat import ascii_escaped
 from ..compat import NOTSET
 from ..compat import NotSetType
 from _pytest.config import Config
+from _pytest.deprecated import _warn_auto_stacklevel
 from _pytest.deprecated import check_ispytest
 from _pytest.deprecated import MARKED_FIXTURE
 from _pytest.outcomes import fail
@@ -353,7 +353,7 @@
             func = args[0]
             is_class = inspect.isclass(func)
             if len(args) == 1 and (istestfunc(func) or is_class):
-                store_mark(func, self.mark, stacklevel=3)
+                store_mark(func, self.mark)
                 return func
         return self.with_args(*args, **kwargs)
 
@@ -408,7 +408,7 @@
         yield mark_obj
 
 
-def store_mark(obj, mark: Mark, *, stacklevel: int = 2) -> None:
+def store_mark(obj, mark: Mark) -> None:
     """Store a Mark on an object.
 
     This is used to implement the Mark declarations/decorators correctly.
@@ -418,7 +418,7 @@
     from ..fixtures import getfixturemarker
 
     if getfixturemarker(obj) is not None:
-        warnings.warn(MARKED_FIXTURE, stacklevel=stacklevel)
+        _warn_auto_stacklevel(MARKED_FIXTURE)
 
     # Always reassign name to avoid updating pytestmark in a reference that
     # was only borrowed.
@@ -543,12 +543,11 @@
                     __tracebackhide__ = True
                     fail(f"Unknown '{name}' mark, did you mean 'parametrize'?")
 
-                warnings.warn(
+                _warn_auto_stacklevel(
                     f"Unknown pytest.mark.{name} - is this a typo?  You can register "
                     "custom marks to avoid this warning - for details, see "
                     "https://docs.pytest.org/en/stable/how-to/mark.html",
                     PytestUnknownMarkWarning,
-                    2,
                 )
 
         return MarkDecorator(Mark(name, (), {}, _ispytest=True), _ispytest=True)

testing/deprecated_test.py

@@ -59,7 +59,7 @@ def pytest_runtest_call(self):
 
     with pytest.warns(
         PytestDeprecationWarning,
-        match=r"Please use the pytest.hookimpl\(tryfirst=True\)",
+        match=r"Please use the pytest\.hookimpl\(tryfirst=True\)",
     ) as recorder:
         pm.register(DeprecatedMarkImplPlugin())
     (record,) = recorder
@@ -185,6 +185,22 @@ def foo():
     # from applying @fixture twice
     # ValueError("fixture is being applied more than once to the same function")
     assert len(record) == 1
+    # should point to this file
+    assert record[0].filename == __file__
+
+    # Same with a different order
+    with pytest.warns(
+        pytest.PytestRemovedIn9Warning,
+        match=r"Marks applied to fixtures have no effect",
+    ) as record:
+
+        @pytest.mark.parametrize("example", ["hello"])
+        @pytest.fixture
+        def bar():
+            raise NotImplementedError()
+
+    assert len(record) == 1
+    assert record[0].filename == __file__
 
 
 def test_fixture_disallow_marks_on_fixtures():