Issue #21318 has been updated by Eregon (Benoit Daloze). Complete reproducer: ``` $ RUBY_NAMESPACE=1 ruby -ve 'p Module.nesting; ns = Namespace.new; File.write "ns.rb", "p Module.nesting"; ns.require "./ns"' ruby 3.5.0dev (2025-05-10T07:50:29Z namespace-on-read-.. bd4f57f96b) +PRISM [x86_64-linux] ruby: warning: Namespace is experimental, and the behavior may change in the future! See doc/namespace.md for know issues, etc. [] [#<Namespace:24,user,optional>] ``` ---------------------------------------- Bug #21318: Namespaces leak with Module.nesting https://bugs.ruby-lang.org/issues/21318#change-113097 * Author: fxn (Xavier Noria) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Namespaces are not transparent for this program: ```ruby Module.nesting ``` The nesting is empty or not depending on whether it is being executed under a namespace. -- https://bugs.ruby-lang.org/