Fix DeprecationError from ModuleSpec.loader.load_module in Red.load_extension

redbot/core/bot.py

@@ -12,6 +12,7 @@
 from collections import namedtuple, OrderedDict
 from datetime import datetime
 from importlib.machinery import ModuleSpec
+from importlib.util import module_from_spec
 from pathlib import Path
 from typing import (
     Optional,
@@ -1680,16 +1681,22 @@ async def load_extension(self, spec: ModuleSpec):
         name = spec.name.split(".")[-1]
         if name in self.extensions:
             raise errors.PackageAlreadyLoaded(spec)
-
-        lib = spec.loader.load_module()
+        lib = module_from_spec(spec)
+        sys.modules[spec.name] = lib
+        try:
+            spec.loader.exec_module(lib)
+        except Exception:
+            del sys.modules[spec.name]
+            raise
         if not hasattr(lib, "setup"):
             del lib
-            raise discord.ClientException(f"extension {name} does not have a setup function")
+            raise discord.ClientException(f"Extension {name} does not have a setup function.")
 
         try:
             await lib.setup(self)
             await self.tree.red_check_enabled()
-        except Exception as e:
+        except Exception:
+            del sys.modules[spec.name]
             await self._remove_module_references(lib.__name__)
             await self._call_module_finalizers(lib, name)
             raise