Issue #19164 has been reported by byroot (Jean Boussier). ---------------------------------------- Bug #19164: [3.2.0dev] Freezing an object can prevent removing methods on its class https://bugs.ruby-lang.org/issues/19164 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal * Target version: 3.2 * ruby -v: ruby 3.2.0dev (2022-11-30T08:20:38Z master c8bfbbc25e) [arm64-darwin22] * Backport: 2.7: DONTNEED, 3.0: DONTNEED, 3.1: DONTNEED ---------------------------------------- The following snippet showcase the bug. It passes on 3.1 and older, but fails on 3.2.0 ```ruby klass = Class.new klass.prepend(Module.new) klass.new.freeze klass.class_eval do define_method(:bar) {} # works remove_method(:bar) # raise FrozenError end ``` Bisecting with this script points me to [e7b1ff984fde859a7778dec564731eb79392406f](https://github.com/ruby/ruby/commit/e7b1ff984fde859a7778dec564731eb79392406f), which suggest some part of the codebase might be misusing some user flags. I have a patch that fix this script but I doubt it's the right fix, I'll be working with @jemmai and @tenderlovemaking to find a proper fix. I'm opening this ticket to make sure it's addressed before the 3.2.0 final release. -- https://bugs.ruby-lang.org/