[7.2.x] Fix test_cmdline_python_namespace_package (#10789)

Co-authored-by: Bruno Oliveira <nicoddemus@gmail.com>

testing/acceptance_test.py

@@ -694,7 +694,14 @@ def test_cmdline_python_namespace_package(
 
         # mixed module and filenames:
         monkeypatch.chdir("world")
-        result = pytester.runpytest("--pyargs", "-v", "ns_pkg.hello", "ns_pkg/world")
+
+        # pgk_resources.declare_namespace has been deprecated in favor of implicit namespace packages.
+        # While we could change the test to use implicit namespace packages, seems better
+        # to still ensure the old declaration via declare_namespace still works.
+        ignore_w = r"-Wignore:Deprecated call to `pkg_resources.declare_namespace"
+        result = pytester.runpytest(
+            "--pyargs", "-v", "ns_pkg.hello", "ns_pkg/world", ignore_w
+        )
         assert result.ret == 0
         result.stdout.fnmatch_lines(
             [

testing/test_monkeypatch.py

@@ -425,6 +425,9 @@ class A:
     assert A.x == 1
 
 
+@pytest.mark.filterwarnings(
+    "ignore:Deprecated call to `pkg_resources.declare_namespace"
+)
 def test_syspath_prepend_with_namespace_packages(
     pytester: Pytester, monkeypatch: MonkeyPatch
 ) -> None: