[ai misuse] fix(doctest): unwrap mock objects safely during collection

changelog/15333.bugfix.rst

@@ -0,0 +1 @@
+Fixed excessive memory usage during doctest collection on modules importing ``unittest.mock.call`` when the recursion limit is raised.

src/_pytest/doctest.py

@@ -547,6 +547,22 @@ def _find_lineno(self, obj, source_lines):
                         source_lines,
                     )
 
+            def _find(
+                self, tests, obj, name, module, source_lines, globs, seen
+            ) -> None:
+                """Override _find to work around issue in stdlib.
+
+                https://github.com/pytest-dev/pytest/issues/3456
+                https://github.com/python/cpython/issues/69718
+                """
+                if _is_mocked(obj):
+                    return  # pragma: no cover
+                with _patch_unwrap_mock_aware():
+                    # Type ignored because this is a private function.
+                    super()._find(  # type:ignore[misc]
+                        tests, obj, name, module, source_lines, globs, seen
+                    )
+
             if sys.version_info < (3, 13):
 
                 def _from_module(self, module, object):

testing/test_doctest.py

@@ -1812,6 +1812,26 @@ class Example(object):
     result.stdout.fnmatch_lines(["* 1 passed *"])
 
 
+def test_doctest_mock_objects_high_recursion_limit(pytester: Pytester) -> None:
+    pytester.makeconftest(
+        """
+        import sys
+        sys.setrecursionlimit(5000)
+        """
+    )
+    pytester.makepyfile(
+        """
+        '''
+        >>> 1
+        1
+        '''
+        from unittest.mock import call
+        """
+    )
+    result = pytester.runpytest("--doctest-modules")
+    result.stdout.fnmatch_lines(["* 1 passed *"])
+
+
 class Broken:
     def __getattr__(self, _):
         raise KeyError("This should be an AttributeError")