Ruby's three dot arguments misreport their parameter types

example.rb

p RUBY_VERSION: RUBY_VERSION

def ab(a, b:)
  [a, {b: b}]
end

puts "Three dots:"
def dots(...) ab(...) end
pp real_sig:    method(:ab).parameters,
   wrapper_sig: method(:dots).parameters,
   result:      dots(123, b: 456)

puts "", "Explicitly reproducing the alleged signature"
def alleged(*rest, &block) ab(*rest, &block) end
pp real_sig:    method(:ab).parameters,
   wrapper_sig: method(:alleged).parameters,
   result:      (alleged(123, b: 456) rescue $!)

puts "", "What I think the sigature actually is"
def actual(*rest, **kwrest, &block) ab(*rest, **kwrest, &block) end
pp real_sig:    method(:ab).parameters,
   wrapper_sig: method(:actual).parameters,
   result:      actual(123, b: 456)
   
__END__
Output:

{:RUBY_VERSION=>"3.0.1"}

Three dots:
{:real_sig=>[[:req, :a], [:keyreq, :b]],
 :wrapper_sig=>[[:rest, :*], [:block, :&]],
 :result=>[123, {:b=>456}]}

Explicitly reproducing the alleged signature
{:real_sig=>[[:req, :a], [:keyreq, :b]],
 :wrapper_sig=>[[:rest, :rest], [:block, :block]],
 :result=>
  #<ArgumentError: wrong number of arguments (given 2, expected 1; required keyword: b)>}

What I think the sigature actually is
{:real_sig=>[[:req, :a], [:keyreq, :b]],
 :wrapper_sig=>[[:rest, :rest], [:keyrest, :kwrest], [:block, :block]],
 :result=>[123, {:b=>456}]}