Add regression test for #6895 (#6898)

* Upgrade astroid to 2.11.6

Co-authored-by: Pierre Sassoulas <pierre.sassoulas@gmail.com>

doc/whatsnew/2/2.14/full.rst

@@ -5,6 +5,12 @@ What's New in Pylint 2.14.2?
 ----------------------------
 Release date: TBA
 
+
+* Fixed a false positive for ``unused-variable`` when a function returns an
+  ``argparse.Namespace`` object.
+
+  Closes #6895
+
 * Avoided raising an identical ``undefined-loop-variable`` message twice on the same line.
 
 * Don't crash if ``lint.run._query_cpu()`` is run within a Kubernetes Pod, that has only

requirements_test_min.txt

@@ -1,6 +1,6 @@
 -e .[testutils,spelling]
 # astroid dependency is also defined in setup.cfg
-astroid==2.11.5  # Pinned to a specific version for tests
+astroid==2.11.6  # Pinned to a specific version for tests
 typing-extensions~=4.2
 pytest~=7.1
 pytest-benchmark~=3.4

setup.cfg

@@ -47,7 +47,7 @@ install_requires =
     # Also upgrade requirements_test_min.txt if you are bumping astroid.
     # Pinned to dev of next minor update to allow editable installs,
     # see https://github.com/PyCQA/astroid/issues/1341
-    astroid>=2.11.5,<=2.12.0-dev0
+    astroid>=2.11.6,<=2.12.0-dev0
     isort>=4.2.5,<6
     mccabe>=0.6,<0.8
     tomli>=1.1.0;python_version<"3.11"

tests/functional/u/unused/unused_variable_after_inference.py

@@ -0,0 +1,7 @@
+"""Regression test for https://github.com/PyCQA/pylint/issues/6895"""
+# pylint: disable=missing-class-docstring,too-few-public-methods
+import argparse
+class Cls:
+    def meth(self):
+        """Enable non-iterator-returned to produce the failure condition"""
+        return argparse.Namespace(debug=True)

tests/functional/u/unused/unused_variable_after_inference.rc

@@ -0,0 +1,2 @@
+[Messages Control]
+enable=non-iterator-returned