Remove support for '[pytest]' section in setup.cfg file

Fix #3086

changelog/3086.removal.rst

@@ -0,0 +1,4 @@
+``[pytest]`` section in **setup.cfg** files is not longer supported, use ``[tool:pytest]`` instead. ``setup.cfg`` files
+are meant for use with ``distutils``, and a section named ``pytest`` has notoriously been a source of conflicts and bugs.
+
+Note that for **pytest.ini** and **tox.ini** files the section remains ``[pytest]``.

doc/en/deprecations.rst

@@ -125,15 +125,6 @@ To update the code, use ``pytest.param``:
 
 
 
-
-[pytest] section in setup.cfg files
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-.. deprecated:: 3.0
-
-``[pytest]`` sections in ``setup.cfg`` files should now be named ``[tool:pytest]``
-to avoid conflicts with other distutils commands.
-
 Result log (``--result-log``)
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -185,6 +176,16 @@ Switch over to the ``@pytest.fixture`` decorator:
         return SomeData()
 
 
+
+[pytest] section in setup.cfg files
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+*Removed in version 4.0.*
+
+``[pytest]`` sections in ``setup.cfg`` files should now be named ``[tool:pytest]``
+to avoid conflicts with other distutils commands.
+
+
 Metafunc.addcall
 ~~~~~~~~~~~~~~~~
 

src/_pytest/config/findpaths.py

@@ -3,6 +3,7 @@ import os
 import py
 
 from .exceptions import UsageError
+from _pytest.outcomes import fail
 
 
 def exists(path, ignore=EnvironmentError):
@@ -34,15 +35,10 @@ def getcfg(args, config=None):
                     iniconfig = py.iniconfig.IniConfig(p)
                     if "pytest" in iniconfig.sections:
                         if inibasename == "setup.cfg" and config is not None:
-                            from _pytest.warnings import _issue_warning_captured
-                            from _pytest.warning_types import RemovedInPytest4Warning
 
-                            _issue_warning_captured(
-                                RemovedInPytest4Warning(
-                                    CFG_PYTEST_SECTION.format(filename=inibasename)
-                                ),
-                                hook=config.hook,
-                                stacklevel=2,
+                            fail(
+                                CFG_PYTEST_SECTION.format(filename=inibasename),
+                                pytrace=False,
                             )
                         return base, p, iniconfig["pytest"]
                     if (
@@ -112,14 +108,9 @@ def determine_setup(inifile, args, rootdir_cmd_arg=None, config=None):
                 inicfg = iniconfig[section]
                 if is_cfg_file and section == "pytest" and config is not None:
                     from _pytest.deprecated import CFG_PYTEST_SECTION
-                    from _pytest.warnings import _issue_warning_captured
 
-                    # TODO: [pytest] section in *.cfg files is deprecated. Need refactoring once
-                    # the deprecation expires.
-                    _issue_warning_captured(
-                        CFG_PYTEST_SECTION.format(filename=str(inifile)),
-                        config.hook,
-                        stacklevel=2,
+                    fail(
+                        CFG_PYTEST_SECTION.format(filename=str(inifile)), pytrace=False
                     )
                 break
             except KeyError:

src/_pytest/deprecated.py

@@ -14,7 +14,6 @@ from __future__ import print_function
 
 from _pytest.warning_types import PytestDeprecationWarning
 from _pytest.warning_types import RemovedInPytest4Warning
-from _pytest.warning_types import UnformattedWarning
 
 
 YIELD_TESTS = "yield tests were removed in pytest 4.0 - {name} will be ignored"
@@ -31,10 +30,7 @@ FIXTURE_NAMED_REQUEST = PytestDeprecationWarning(
     "'request' is a reserved name for fixtures and will raise an error in future versions"
 )
 
-CFG_PYTEST_SECTION = UnformattedWarning(
-    RemovedInPytest4Warning,
-    "[pytest] section in {filename} files is deprecated, use [tool:pytest] instead.",
-)
+CFG_PYTEST_SECTION = "[pytest] section in {filename} files is no longer supported, change to [tool:pytest] instead."
 
 GETFUNCARGVALUE = RemovedInPytest4Warning(
     "getfuncargvalue is deprecated, use getfixturevalue"

testing/deprecated_test.py

@@ -10,8 +10,7 @@ from _pytest.warnings import SHOW_PYTEST_WARNINGS_ARG
 pytestmark = pytest.mark.pytester_example_path("deprecated")
 
 
-@pytest.mark.filterwarnings("default")
-def test_pytest_setup_cfg_deprecated(testdir):
+def test_pytest_setup_cfg_unsupported(testdir):
     testdir.makefile(
         ".cfg",
         setup="""
@@ -19,14 +18,11 @@ def test_pytest_setup_cfg_deprecated(testdir):
         addopts = --verbose
     """,
     )
-    result = testdir.runpytest()
-    result.stdout.fnmatch_lines(
-        ["*pytest*section in setup.cfg files is deprecated*use*tool:pytest*instead*"]
-    )
+    with pytest.raises(pytest.fail.Exception):
+        testdir.runpytest()
 
 
-@pytest.mark.filterwarnings("default")
-def test_pytest_custom_cfg_deprecated(testdir):
+def test_pytest_custom_cfg_unsupported(testdir):
     testdir.makefile(
         ".cfg",
         custom="""
@@ -34,10 +30,8 @@ def test_pytest_custom_cfg_deprecated(testdir):
         addopts = --verbose
     """,
     )
-    result = testdir.runpytest("-c", "custom.cfg")
-    result.stdout.fnmatch_lines(
-        ["*pytest*section in custom.cfg files is deprecated*use*tool:pytest*instead*"]
-    )
+    with pytest.raises(pytest.fail.Exception):
+        testdir.runpytest("-c", "custom.cfg")
 
 
 def test_getfuncargvalue_is_deprecated(request):