Issue #20319 has been updated by matz (Yukihiro Matsumoto). I accept https://github.com/ruby/ruby/pull/10245 Matz. ---------------------------------------- Bug #20319: Singleton class is being frozen lazily in some cases https://bugs.ruby-lang.org/issues/20319#change-116529 * Author: andrykonchin (Andrew Konchin) * Status: Open * ruby -v: 3.2.2 * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- I've noticed suspicious behaviour (it doesn't affect anything in practice for me though) when an object becomes frozen only its own singleton class becomes frozen immediately. A singleton class of the object immediate singleton class becomes frozen lazily after `#singleton_class` method call: ```ruby o = Object.new klass = o.singleton_class.singleton_class o.freeze puts klass.frozen? # false <== here we expect true puts o.singleton_class.singleton_class.frozen? # true puts klass.frozen? # true ``` I would expect all created (and visible to user) singleton classes in an object singleton classes chain to become frozen immediately when the object gets frozen. -- https://bugs.ruby-lang.org/