Issue #19745 has been updated by Eregon (Benoit Daloze). @itarato This example is not the same as the linked issue. I would suggest to open a separate issue to dicuss the original example, which uses `define_method`. (although this `define_singleton_method` example does fail on TruffleRuby, we should fix `define_singleton_method`) ---------------------------------------- Bug #19745: Confirm correct behaviour when attaching private method with `#define_method`/`#define_singleton_method` https://bugs.ruby-lang.org/issues/19745#change-103697 * Author: itarato (Peter Arato) * Status: Closed * Priority: Normal * ruby -v: HEAD * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- Should dynamically added private methods be accessible publicly? See the following example? ```ruby private def bar; end foo = Object.new foo.define_singleton_method(:bar, method(:bar)) foo.bar # No error. ``` The script above runs fine on latest Ruby HEAD. Is this correct to ignore the fact that the added method (`method(:bar)`) is private? This came up during a TruffleRuby investigation (https://github.com/oracle/truffleruby/issues/3134) where the result for the same script is: `private method 'bar' called for #<Object:0xc8> (NoMethodError)` -- https://bugs.ruby-lang.org/