Issue #20092 has been updated by nobu (Nobuyoshi Nakada). The behavior in 3.4.0 is correct. It was a bug #20090. ---------------------------------------- Bug #20092: Warnings for anonymous parameters do not display in Ruby 3.4dev https://bugs.ruby-lang.org/issues/20092#change-105883 * Author: koic (Koichi ITO) * Status: Open * Priority: Normal * ruby -v: ruby 3.4.0dev (2023-12-26T22:32:38Z master be92bf4ff4) [x86_64-darwin22] * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- I encountered no expected warnings in Ruby 3.4dev. ## Reproduction code ```ruby def anonymous(*, **, &) rest_block do foo(*) end kwrest_block do bar(**) end block_block do baz(&) end end ``` ## Expected Behavior (Ruby 3.3.0) Warnings are displayed: ```ruby $ ruby -vc example.rb ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [x86_64-darwin22] example.rb: example.rb:3: anonymous rest parameter is also used within block (SyntaxError) example.rb:7: anonymous keyword rest parameter is also used within block example.rb:11: anonymous block parameter is also used within block ``` ## Actual Behavior (Ruby 3.4dev) No warning displayed: ```ruby $ ruby -vc example.rb ruby 3.4.0dev (2023-12-26T22:32:38Z master be92bf4ff4) [x86_64-darwin22] Syntax OK ``` -- https://bugs.ruby-lang.org/