brief the news

Fixes a race condition in importlib's module loading when using lazy submodules, preventing RecursionError in multi-threaded scenarios.

Author: SwayamInSync

Misc/NEWS.d/next/Library/2026-05-12-22-00-00.gh-issue-149728.LzyImp.rst

@@ -1,7 +1 @@
-Fix a race in :mod:`importlib._bootstrap` where the fast path in
-``_find_and_load`` could return a module whose ``parent.child`` attribute had
-not yet been set. Under free-threaded CPython this caused packages using the
-lazy-submodule ``__getattr__`` pattern (e.g. NumPy) to recurse to
-:exc:`RecursionError` when multiple threads first-touched the same lazy
-submodule concurrently. ``spec._initializing`` is now kept ``True`` until
-after ``_find_and_load_unlocked`` has attached the module to its parent.
+fix race in importlib when importing module which defined getattr