Document vars behavior when __dict__ is missing (#21466)
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 43c47c1..d381d43 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -1734,6 +1734,9 @@
locals dictionary is only useful for reads since updates to the locals
dictionary are ignored.
+ A :exc:`TypeError` exception is raised if an object is specified but
+ it doesn't have a :attr:`~object.__dict__` attribute (for example, if
+ its class defines the :attr:`~object.__slots__` attribute).
.. function:: zip(*iterables, strict=False)