Ref: https://sourceforge.net/p/ruamel-yaml-clib/code/ci/dd6339faf0f6bb1b5ac99c92fd3d0b8b25412c72/
Adapted for ruamel.std.pathlib 0.12.0.
---
diff -rupN a/setup.py b/setup.py
--- a/setup.py	2023-02-06 09:33:09.000000000 +0000
+++ b/setup.py	2026-03-23 03:06:48.490000000 +0000
@@ -13,7 +13,7 @@ import traceback
 
 sys.path = [path for path in sys.path if path not in [os.getcwd(), ""]]
 import platform  # NOQA
-from _ast import *  # NOQA
+import _ast as Ast  # NOQA
 from ast import parse  # NOQA
 
 from setuptools import setup, Extension, Distribution  # NOQA
@@ -37,11 +37,6 @@ if __name__ != '__main__':
 
 full_package_name = None
 
-if sys.version_info < (3,):
-    string_type = basestring
-else:
-    string_type = str
-
 
 if sys.version_info < (3, 4):
 
@@ -80,10 +75,6 @@ else:
             print(*args, **kw1)
 
 
-if sys.version_info >= (3, 8):
-    from ast import Str, Num, Bytes, NameConstant  # NOQA
-
-
 def literal_eval(node_or_string):
     """
     Safely evaluate an expression node or a string containing a Python
@@ -94,59 +85,47 @@ def literal_eval(node_or_string):
     Even when passing in Unicode, the resulting Str types parsed are 'str' in Python 2.
     I don't now how to set 'unicode_literals' on parse -> Str is explicitly converted.
     """
-    _safe_names = {'None': None, 'True': True, 'False': False}
-    if isinstance(node_or_string, string_type):
+    if isinstance(node_or_string, str):
         node_or_string = parse(node_or_string, mode='eval')
-    if isinstance(node_or_string, Expression):
+    if isinstance(node_or_string, Ast.Expression):
         node_or_string = node_or_string.body
     else:
         raise TypeError('only string or AST nodes supported')
 
     def _convert(node):
-        if isinstance(node, Str):
-            if sys.version_info < (3,) and not isinstance(node.s, unicode):
-                return node.s.decode('utf-8')
-            return node.s
-        elif isinstance(node, Bytes):
-            return node.s
-        elif isinstance(node, Num):
-            return node.n
-        elif isinstance(node, Tuple):
+        if isinstance(node, Ast.Constant):
+            return node.value
+        elif isinstance(node, Ast.Tuple):
             return tuple(map(_convert, node.elts))
-        elif isinstance(node, List):
+        elif isinstance(node, Ast.List):
             return list(map(_convert, node.elts))
-        elif isinstance(node, Set):
+        elif isinstance(node, Ast.Set):
             return set(map(_convert, node.elts))
-        elif isinstance(node, Dict):
-            return dict((_convert(k), _convert(v)) for k, v in zip(node.keys, node.values))
-        elif isinstance(node, NameConstant):
-            return node.value
-        elif sys.version_info < (3, 4) and isinstance(node, Name):
-            if node.id in _safe_names:
-                return _safe_names[node.id]
+        elif isinstance(node, Ast.Dict):
+             return {_convert(k): _convert(v) for k, v in zip(node.keys, node.values)}
         elif (
-            isinstance(node, UnaryOp)
-            and isinstance(node.op, (UAdd, USub))
-            and isinstance(node.operand, (Num, UnaryOp, BinOp))
+            isinstance(node, Ast.UnaryOp)
+            and isinstance(node.op, (Ast.UAdd, Ast.USub))
+            and isinstance(node.operand, (Ast.Num, Ast.UnaryOp, Ast.BinOp))
         ):  # NOQA
             operand = _convert(node.operand)
-            if isinstance(node.op, UAdd):
+            if isinstance(node.op, Ast.UAdd):
                 return +operand
             else:
                 return -operand
         elif (
-            isinstance(node, BinOp)
-            and isinstance(node.op, (Add, Sub))
-            and isinstance(node.right, (Num, UnaryOp, BinOp))
-            and isinstance(node.left, (Num, UnaryOp, BinOp))
+            isinstance(node, Ast.BinOp)
+            and isinstance(node.op, (Ast.Add, Ast.Sub))
+            and isinstance(node.right, (Ast.Num, Ast.UnaryOp, Ast.BinOp))
+            and isinstance(node.left, (Ast.Num, Ast.UnaryOp, Ast.BinOp))
         ):  # NOQA
             left = _convert(node.left)
             right = _convert(node.right)
-            if isinstance(node.op, Add):
+            if isinstance(node.op, Ast.Add):
                 return left + right
             else:
                 return left - right
-        elif isinstance(node, Call):
+        elif isinstance(node, Ast.Call):
             func_id = getattr(node.func, 'id', None)
             if func_id == 'dict':
                 return dict((k.arg, _convert(k.value)) for k in node.keywords)
@@ -646,7 +625,7 @@ class NameSpacePackager(object):
             return self._pkg
         # 'any' for all builds, 'py27' etc for specifics versions
         packages = ir.get('any', [])
-        if isinstance(packages, string_type):
+        if isinstance(packages, str):
             packages = packages.split()  # assume white space separated string
         if self.nested:
             # parent dir is also a package, make sure it is installed (need its .pth file)