gh-149321: Fix stdlib imports with lazy imports disabled (#149338)

Author: pablogsal

Lib/ast.py

@@ -21,7 +21,6 @@
 :license: Python License.
 """
 from _ast import *
-lazy from _colorize import can_colorize, get_theme
 
 
 def parse(source, filename='<unknown>', mode='exec', *,
@@ -142,6 +141,8 @@ def dump(
     If show_empty is False, then empty lists and fields that are None
     will be omitted from the output for better readability.
     """
+    from _colorize import get_theme
+
     t = get_theme(force_color=color, force_no_color=not color).ast
 
     def _format(node, level=0):
@@ -708,6 +709,7 @@ def main(args=None):
 
     tree = parse(source, name, args.mode, type_comments=args.no_type_comments,
                  feature_version=feature_version, optimize=args.optimize)
+    from _colorize import can_colorize
     print(dump(tree, include_attributes=args.include_attributes,
                color=can_colorize(file=sys.stdout),
                indent=args.indent, show_empty=args.show_empty))

Lib/dataclasses.py

@@ -6,7 +6,6 @@
 import abc
 from reprlib import recursive_repr
 lazy import copy
-lazy import inspect
 lazy import re
 
 
@@ -981,6 +980,7 @@ def __get__(self, _obj, cls):
         try:
             # In some cases fetching a signature is not possible.
             # But, we surely should not fail in this case.
+            import inspect
             text_sig = str(inspect.signature(
                  cls,
                  annotation_format=annotationlib.Format.FORWARDREF,
@@ -1391,6 +1391,7 @@ def _add_slots(cls, is_frozen, weakref_slot, defined_fields):
 
         # If this is a wrapped function, unwrap it.
         if not isinstance(member, type) and hasattr(member, '__wrapped__'):
+            import inspect
             member = inspect.unwrap(member)
 
         if isinstance(member, types.FunctionType):

Lib/test/test_lazy_import/__init__.py

@@ -1034,6 +1034,50 @@ def test_cli_lazy_imports_none_forces_all_imports_eager(self):
         self.assertEqual(result.returncode, 0, f"stderr: {result.stderr}")
         self.assertIn("EAGER", result.stdout)
 
+    @support.requires_resource("cpu")
+    def test_cli_lazy_imports_modes_import_stdlib_modules(self):
+        """-X lazy_imports modes should import available stdlib modules."""
+        # Do not smoke-test modules with intentional import-time effects.
+        import_side_effect_modules = {"antigravity", "this"}
+        importable = []
+
+        for module in sorted(sys.stdlib_module_names):
+            if module in import_side_effect_modules:
+                continue
+
+            with self.subTest(module=module):
+                code = f"import {module}; print({module})"
+                baseline = subprocess.run(
+                    [sys.executable, "-I", "-c", code],
+                    capture_output=True,
+                    text=True,
+                    timeout=60,
+                )
+                if baseline.returncode:
+                    # sys.stdlib_module_names includes modules for other
+                    # platforms and optional extension modules not built here.
+                    continue
+                importable.append(module)
+
+                for mode in ("normal", "none"):
+                    with self.subTest(module=module, mode=mode):
+                        result = subprocess.run(
+                            [
+                                sys.executable,
+                                "-I",
+                                "-X",
+                                f"lazy_imports={mode}",
+                                "-c",
+                                code,
+                            ],
+                            capture_output=True,
+                            text=True,
+                            timeout=60,
+                        )
+                        self.assertEqual(result.returncode, 0, result.stderr)
+
+        self.assertGreater(len(importable), 100)
+
     def test_cli_lazy_imports_normal_respects_lazy_keyword_only(self):
         """-X lazy_imports=normal should respect lazy keyword only."""
         # Note: Use test modules instead of stdlib modules to avoid

Misc/NEWS.d/next/Library/2026-05-03-12-00-00.gh-issue-149321.fUaxrz.rst

@@ -0,0 +1,2 @@
+Fix import cycles exposed by running standard library modules with
+``-X lazy_imports=none``.