diff -u -i -p -F '^(def' -b -w -B /usr/local/Cellar/python\@3.9/3.9.0_2/Frameworks/Python.framework/Versions/3.9/lib/python3.9/ast.py.old /usr/local/Cellar/python\@3.9/3.9.0_2/Frameworks/Python.framework/Versions/3.9/lib/python3.9/ast.py
--- /usr/local/Cellar/python@3.9/3.9.0_2/Frameworks/Python.framework/Versions/3.9/lib/python3.9/ast.py.old	2020-10-05 11:29:48.000000000 -0400
+++ /usr/local/Cellar/python@3.9/3.9.0_2/Frameworks/Python.framework/Versions/3.9/lib/python3.9/ast.py	2020-12-03 15:19:04.000000000 -0500
@@ -63,7 +63,9 @@ def literal_eval(node_or_string):
     if isinstance(node_or_string, Expression):
         node_or_string = node_or_string.body
     def _raise_malformed_node(node):
-        raise ValueError(f'malformed node or string: {node!r}')
+        raise ValueError(f'malformed node or string: {node!r}'
+                         f' at {node.lineno}:{node.col_offset}'
+                         f' .. {node.end_lineno}:{node.end_col_offset}')
     def _convert_num(node):
         if not isinstance(node, Constant) or type(node.value) not in (int, float, complex):
             _raise_malformed_node(node)

Diff finished.  Thu Dec  3 15:19:07 2020