PEP 668 test debug

Author: notatallshaw

tests/functional/test_pep668.py

@@ -37,9 +37,14 @@ def check_externally_managed():
     ],
 )
 @pytest.mark.usefixtures("patch_check_externally_managed")
-def test_fails(script: PipTestEnvironment, arguments: List[str]) -> None:
+def test_fails(script: PipTestEnvironment, arguments: List[str], virtualenv: VirtualEnvironment) -> None:
     result = script.pip(*arguments, "pip", expect_error=True)
-    assert "I am externally managed" in result.stderr
+    try:
+        assert "I am externally managed" in result.stderr
+    except AssertionError:
+        print("virtualenv.sitecustomize:")
+        print(virtualenv.sitecustomize)
+        raise
 
 
 @pytest.mark.parametrize(