Issue #20570 has been updated by austin (Austin Ziegler). I believe you’re *defining* with `**nil`, not *calling* with `**nil`. Your test should probably be `def foo(*, **); end; p foo(*[], **nil)`. This does seem to be a bit of a regression for your particular use case. ---------------------------------------- Bug #20570: Nokey behavior changed since 3.3. https://bugs.ruby-lang.org/issues/20570#change-108766 * Author: ksss (Yuki Kurihara) * Status: Open * ruby -v: ruby 3.3.2 (2024-05-30 revision e5a195edf6) [arm64-darwin22] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- I am using code that transfers the following method call, but found that the behavior has changed since CRuby 3.3. ```ruby receiver_value = Set.new method_name = :merge args = [1] kwargs = {} block = nil receiver_value.__send__(method_name, *args, **kwargs, &block) # => no keywords accepted (ArgumentError) ``` Upon investigation, I found that the behavior of calling a method using `**nil` has changed starting from version 3.3. ``` $ docker run -it --rm rubylang/all-ruby env ALL_RUBY_SINCE=ruby-2.6 ./all-ruby -e 'def foo(*, **nil); end; p foo(*[], **{})' WARNING: The requested image's platform (linux/amd64) does not match the detected host platform (linux/arm64/v8) and no specific platform was requested ruby-2.6.0 -e:1: syntax error, unexpected nil, expecting ')' def foo(*, **nil); end; p foo(*[], **{}) ^~~ exit 1 ... ruby-2.6.10 -e:1: syntax error, unexpected nil, expecting ')' def foo(*, **nil); end; p foo(*[], **{}) ^~~ exit 1 ruby-2.7.0-preview1 -e:1: syntax error, unexpected `nil', expecting ')' def foo(*, **nil); end; p foo(*[], **{}) ^~~ exit 1 ruby-2.7.0-preview2 nil ... ruby-3.2.4 nil ruby-3.3.0-preview1 -e:1:in `<main>': no keywords accepted (ArgumentError) def foo(*, **nil); end; p foo(*[], **{}) ^^^^^^^^^ exit 1 ... ruby-3.3.2 -e:1:in `<main>': no keywords accepted (ArgumentError) def foo(*, **nil); end; p foo(*[], **{}) ^^^^^^^^^ exit 1 ruby-3.4.0-preview1 -e:1:in '<main>': no keywords accepted (ArgumentError) def foo(*, **nil); end; p foo(*[], **{}) ^^^^^^^^^ exit 1 ``` Is this change intentional? -- https://bugs.ruby-lang.org/