Issue #22205 has been updated by Eregon (Benoit Daloze). Ah one more thing I wanted to mention is it might still be possible to support Ruby 2.7 in gems without `ruby2_keywords` by using `def foo(...); bar(...); end` which was introduced in Ruby 2.7.2 (although that does not cover all delegation cases). But I wouldn't recommend it, having to reason about "keywords arguments in Ruby < 3" and "keywords arguments in Ruby >= 3" is very hard as they are quite different concepts. ---------------------------------------- Feature #22205: Deprecate ruby2_keywords https://bugs.ruby-lang.org/issues/22205#change-118241 * Author: shugo (Shugo Maeda) * Status: Open ---------------------------------------- I believe ruby2_keywords should be removed in the future, but removing it now would cause compatibility issues. As a first step, how about adding deprecation warnings to ruby2_keywords? At least the following methods should emit a warning: * Module#ruby2_keywords * main.ruby2_keywords * Proc#ruby2_keywords The following methods are relatively harmless, so it might be better not to warn on them in the first step: * Hash.ruby2_keywords_hash? * Hash.ruby2_keywords_hash ## Background and Motivation While implementing Proc#refined, I noticed that the ruby2_keywords flag on an iseq (param.flags.ruby2_keywords) can be mutated by Proc#ruby2_keywords even when the iseq is shared among multiple Ractors, which is not Ractor-safe. I consider ruby2_keywords a negative legacy, and I would rather deprecate it than fix such behavior. ## Schedule ### For Module#ruby2_keywords, main.ruby2_keywords, and Proc#ruby2_keywords * 4.1: Documentation-only deprecation * 4.2: Verbose-mode deprecation warning * 4.3: Non-verbose-mode deprecation warning * 4.4: Removal ### For Hash.ruby2_keywords_hash?, Hash.ruby2_keywords_hash * 4.1: Documentation-only deprecation * 4.2: No warnings, still working as migration tools * 4.3: Verbose-mode deprecation warning * 4.4: Non-verbose-mode deprecation warning. Hash.ruby2_keywords_hash? always returns false, and Hash.ruby2_keywords_hash returns a plain duplicate of the given hash * 4.5: Removal -- https://bugs.ruby-lang.org/