Issue #21330 has been updated by tagomoris (Satoshi Tagomori). The frozen flag is what I missed. I think we should move the flag to `rb_classext_t`. ---------------------------------------- Bug #21330: Namespace: Class and Module frozen status is not namespaced https://bugs.ruby-lang.org/issues/21330#change-113201 * Author: byroot (Jean Boussier) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- ```ruby File.write("/tmp/test.rb", <<~'RUBY') Hash.freeze RUBY ns = Namespace.new ns.require("/tmp/test.rb") class Hash def monkey_patch end end ``` Expected behavior: Since the monkey patch is in a different namespace, I'd expect it to not impact code that is running in another namespace. Actual behavior: ``` test.rb:9:in '<class:Hash>': can't modify frozen class: Hash (FrozenError) ``` The class is frozen globally, breaking code in other namespaces. Is this by design, or does that mean the frozen status need to be moved in the `classext_t` as well? cc @tagomoris -- https://bugs.ruby-lang.org/