test.rb

def bar(a, b, c)
  puts [a, b, c]
end

def foo(...)
  bar(1, ...)
end

foo(1, 2)

# ruby --version                                                                                                                                                                                                                                                                 
ruby 2.7.8p225 (2023-03-30 revision 1f4d455848) [aarch64-linux]

# ruby test.rb                                                                                                                                                                                                                                                                   
1
1
2

#  ruby --version                                                                                                                                                                                                                                                            
ruby 2.7.0p0 (2019-12-25 revision 647ee6f091) [aarch64-linux]

# ruby test.rb
test.rb:6: syntax error, unexpected ')'
  bar(1, ...)
test.rb:9: syntax error, unexpected end-of-input, expecting `end'