nodes: fix tracebacks from collection errors are not getting pruned (#11711)

Fix #11710.

changelog/11710.bugfix.rst

@@ -0,0 +1 @@
+Fixed tracebacks from collection errors not getting pruned.

src/_pytest/nodes.py

@@ -579,7 +579,7 @@ class Collector(Node, abc.ABC):
             ntraceback = traceback.cut(path=self.path)
             if ntraceback == traceback:
                 ntraceback = ntraceback.cut(excludepath=tracebackcutdir)
-            return excinfo.traceback.filter(excinfo)
+            return ntraceback.filter(excinfo)
         return excinfo.traceback
 
 

testing/test_collection.py

@@ -345,6 +345,29 @@ class TestPrunetraceback:
         result = pytester.runpytest(p)
         result.stdout.fnmatch_lines(["*ERROR collecting*", "*header1*"])
 
+    def test_collection_error_traceback_is_clean(self, pytester: Pytester) -> None:
+        """When a collection error occurs, the report traceback doesn't contain
+        internal pytest stack entries.
+
+        Issue #11710.
+        """
+        pytester.makepyfile(
+            """
+            raise Exception("LOUSY")
+            """
+        )
+        result = pytester.runpytest()
+        result.stdout.fnmatch_lines(
+            [
+                "*ERROR collecting*",
+                "test_*.py:1: in <module>",
+                '    raise Exception("LOUSY")',
+                "E   Exception: LOUSY",
+                "*= short test summary info =*",
+            ],
+            consecutive=True,
+        )
+
 
 class TestCustomConftests:
     def test_ignore_collect_path(self, pytester: Pytester) -> None: