use importlib instead of pkgutil

CHANGES.rst

@@ -3,6 +3,8 @@ Version 2.3.3
 
 Unreleased
 
+-   Python 3.12 compatibility.
+
 
 Version 2.3.2
 -------------

src/flask/helpers.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
+import importlib.util
 import os
-import pkgutil
 import socket
 import sys
 import typing as t
@@ -575,7 +575,8 @@ def get_root_path(import_name: str) -> str:
         return os.path.dirname(os.path.abspath(mod.__file__))
 
     # Next attempt: check the loader.
-    loader = pkgutil.get_loader(import_name)
+    spec = importlib.util.find_spec(import_name)
+    loader = spec.loader if spec is not None else None
 
     # Loader does not exist or we're referring to an unloaded main
     # module or a main module without path (interactive sessions), go

src/flask/scaffold.py

@@ -3,7 +3,6 @@ from __future__ import annotations
 import importlib.util
 import os
 import pathlib
-import pkgutil
 import sys
 import typing as t
 from collections import defaultdict
@@ -856,7 +855,8 @@ def _find_package_path(import_name):
             return os.path.dirname(root_spec.origin)
 
     # we were unable to find the `package_path` using PEP 451 loaders
-    loader = pkgutil.get_loader(root_mod_name)
+    spec = importlib.util.find_spec(root_mod_name)
+    loader = spec.loader if spec is not None else None
 
     if loader is None or root_mod_name == "__main__":
         # import name is not found, or interactive/main module