[] ~/projects/jruby $ jruby -e 'def foo(a); end; def bar; a = [1,2]; foo(*a); end; bar'
ArgumentError: wrong number of arguments (given 2, expected 1)
     foo at -e:1
     bar at -e:1
  <main> at -e:1

[] ~/projects/jruby $ rvm jruby-9.2.19.0 do ruby -e 'def foo(a); end; def bar; a = [1,2]; foo(*a); end; bar'
ArgumentError: wrong number of arguments (given 2, expected 1)
     bar at -e:1
  <main> at -e:1