Adjust stacklevel of "config" warnings

Related to pytest-dev#4439

Author: nicoddemus

src/_pytest/assertion/rewrite.py

@@ -270,6 +270,7 @@ def _warn_already_imported(self, name):
         _issue_config_warning(
             PytestWarning("Module already imported so cannot be rewritten: %s" % name),
             self.config,
+            stacklevel=5,
         )
 
     def load_module(self, name):

src/_pytest/cacheprovider.py

@@ -56,7 +56,9 @@ def warn(self, fmt, **args):
         from _pytest.warning_types import PytestWarning
 
         _issue_config_warning(
-            PytestWarning(fmt.format(**args) if args else fmt), self._config
+            PytestWarning(fmt.format(**args) if args else fmt),
+            self._config,
+            stacklevel=3,
         )
 
     def makedir(self, name):

src/_pytest/config/__init__.py

@@ -191,7 +191,7 @@ def _prepareconfig(args=None, plugins=None):
         if warning:
             from _pytest.warnings import _issue_config_warning
 
-            _issue_config_warning(warning, config=config)
+            _issue_config_warning(warning, config=config, stacklevel=4)
         return pluginmanager.hook.pytest_cmdline_parse(
             pluginmanager=pluginmanager, args=args
         )

src/_pytest/config/findpaths.py

@@ -42,6 +42,7 @@ def getcfg(args, config=None):
                                     CFG_PYTEST_SECTION.format(filename=inibasename)
                                 ),
                                 config=config,
+                                stacklevel=2,
                             )
                         return base, p, iniconfig["pytest"]
                     if (
@@ -116,7 +117,9 @@ def determine_setup(inifile, args, rootdir_cmd_arg=None, config=None):
                     # TODO: [pytest] section in *.cfg files is deprecated. Need refactoring once
                     # the deprecation expires.
                     _issue_config_warning(
-                        CFG_PYTEST_SECTION.format(filename=str(inifile)), config
+                        CFG_PYTEST_SECTION.format(filename=str(inifile)),
+                        config,
+                        stacklevel=2,
                     )
                 break
             except KeyError:

src/_pytest/resultlog.py

@@ -36,7 +36,7 @@ def pytest_configure(config):
         from _pytest.deprecated import RESULT_LOG
         from _pytest.warnings import _issue_config_warning
 
-        _issue_config_warning(RESULT_LOG, config)
+        _issue_config_warning(RESULT_LOG, config, stacklevel=2)
 
 
 def pytest_unconfigure(config):

src/_pytest/warnings.py

@@ -160,18 +160,19 @@ def pytest_terminal_summary(terminalreporter):
         yield
 
 
-def _issue_config_warning(warning, config):
+def _issue_config_warning(warning, config, stacklevel):
     """
     This function should be used instead of calling ``warnings.warn`` directly when we are in the "configure" stage:
     at this point the actual options might not have been set, so we manually trigger the pytest_warning_captured
     hook so we can display this warnings in the terminal. This is a hack until we can sort out #2891.
 
     :param warning: the warning instance.
     :param config:
+    :param stacklevel: stacklevel forwarded to warnings.warn
     """
     with warnings.catch_warnings(record=True) as records:
         warnings.simplefilter("always", type(warning))
-        warnings.warn(warning, stacklevel=2)
+        warnings.warn(warning, stacklevel=stacklevel)
     config.hook.pytest_warning_captured.call_historic(
         kwargs=dict(warning_message=records[0], when="config", item=None)
     )

testing/test_warnings.py

@@ -310,7 +310,7 @@ def test_warning_captured_hook(testdir):
         """
         from _pytest.warnings import _issue_config_warning
         def pytest_configure(config):
-            _issue_config_warning(UserWarning("config warning"), config)
+            _issue_config_warning(UserWarning("config warning"), config, stacklevel=2)
     """
     )
     testdir.makepyfile(