Issue #20640 has been updated by jeremyevans0 (Jeremy Evans). Pull request: https://github.com/ruby/ruby/pull/11206 ---------------------------------------- Bug #20640: Evaluation Order Issue in f(**h, &h.delete(key)) https://bugs.ruby-lang.org/issues/20640#change-109162 * Author: jeremyevans0 (Jeremy Evans) * Status: Open * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Since Ruby 3.0, there is an evaluation order issue when passing a single keyword splat and a block pass expression that modifies the keyword splat: ```ruby def f(*a, **kw) kw[:a].class end h = {a: ->{}} f(**h, &h.delete(:a)) # Ruby 2.0 - 2.7: Proc # Ruby 3.0 - 3.4: NilClass ``` For single keyword splats followed by positional argument splats, this has been an issue since 3.3: ```ruby def f(*a, **kw) kw[:a].class end h = {a: ->{}} a = [] f(*a, **h, &h.delete(:a)) # Ruby 2.0 - 3.2: Proc # Ruby 3.3 - 3.4: NilClass ``` Ruby handles these issues for positional splats, duplicating the splatted array before evaluating post, keyword, or block argument expressions: ```ruby f(*a, a.pop) # post argument f(*a, **a.pop) # keyword splat argument f(*a, a: a.pop) # keyword argument f(*a, &a.pop) # block argument ``` So it should handle the case for a keyword splat that could potentially be modified by block argument expression. I'll submit a pull request shortly to fix this issue. -- https://bugs.ruby-lang.org/