Ruby

The following code raises a LocalJumpError at the last line on 2.4 and trunk.
2.3 and earlier work fine.

module M refine String do # or any class end end class C def call(a, x, &b) b.call(a, &x) end end o = C.new x = ->(z){p z} o.call(42, x, &:tap) #=> 42 using M o.call(42, x, &:tap) #=> LocalJumpError