update key to just be cloned

Author: KevinRK29

mypy/build.py

@@ -993,11 +993,10 @@ def __init__(
         self.import_options: dict[str, bytes] = {}
         # Cache for transitive dependency check (expensive).
         self.transitive_deps_cache: dict[tuple[int, int], bool] = {}
-        # Cache for options_snapshot() keyed by id() of the cloned Options.
-        # Most modules share a handful of distinct configs. The keepalive
-        # list keeps clones reachable so id() is stable for cache keys.
-        self.options_snapshot_cache: dict[int, tuple[str, str]] = {}
-        self._options_snapshot_keepalive: list[Options] = []
+        # Cache for options_snapshot() keyed by the cloned Options. Options is
+        # hashed by identity, and most modules share a handful of distinct
+        # configs, so this collapses ~all calls onto a few entries.
+        self.options_snapshot_cache: dict[Options, tuple[str, str]] = {}
         # Packages for which we know presence or absence of __getattr__().
         self.known_partial_packages: dict[str, bool] = {}
 
@@ -1986,16 +1985,13 @@ def options_snapshot(module: str, manager: BuildManager) -> dict[str, object]:
             result[key] = val
         return result
     cache = manager.options_snapshot_cache
-    key = id(cloned)
-    cached = cache.get(key)
+    cached = cache.get(cloned)
     if cached is None:
         platform_opt, values = cloned.select_options_affecting_cache()
         buf = WriteBuffer()
         write_json_value(buf, cast(JsonValue, values))
         cached = (platform_opt, hash_digest(buf.getvalue()))
-        cache[key] = cached
-        # Keep cloned reachable so its id() is not reused by a later clone.
-        manager._options_snapshot_keepalive.append(cloned)
+        cache[cloned] = cached
     return {"platform": cached[0], "other_options": cached[1]}