Merge "add slotscheck to CI" into main

2 files changed, 10 insertions, 4 deletions

diff --git a/lib/sqlalchemy/util/_has_cy.py b/lib/sqlalchemy/util/_has_cy.py
index bf251b5b5..b09338f21 100644
--- a/lib/sqlalchemy/util/_has_cy.py
+++ b/lib/sqlalchemy/util/_has_cy.py
@@ -1,11 +1,15 @@
+import os
 import typing
 
 if not typing.TYPE_CHECKING:
-    try:
-        from ..cyextension import util  # noqa
-    except ImportError:
+    if os.environ.get("DISABLE_SQLALCHEMY_CEXT_RUNTIME"):
         HAS_CYEXTENSION = False
     else:
-        HAS_CYEXTENSION = True
+        try:
+            from ..cyextension import util  # noqa
+        except ImportError:
+            HAS_CYEXTENSION = False
+        else:
+            HAS_CYEXTENSION = True
 else:
     HAS_CYEXTENSION = False
diff --git a/lib/sqlalchemy/util/_py_collections.py b/lib/sqlalchemy/util/_py_collections.py
index fd149d5bb..9bf5c3546 100644
--- a/lib/sqlalchemy/util/_py_collections.py
+++ b/lib/sqlalchemy/util/_py_collections.py
@@ -18,6 +18,8 @@ _VT = TypeVar("_VT", bound=Any)
 
 
 class ImmutableContainer:
+    __slots__ = ()
+
     def _immutable(self, *arg: Any, **kw: Any) -> NoReturn:
         raise TypeError("%s object is immutable" % self.__class__.__name__)