I get a segfault trying to define two handlers successively, even if I off() them after each use.

#!ruby

require 'ruby2d'

set width: 1000

def a
  clear

  evt = on :key_down do |event|
    close if event.key == 'return'
  end

  show

  off evt
end

a
a

puts 'end'

What happens is that I start the script, the first a is called, I press Enter, the same method is called again, I press Enter again and so close is called, then the method ends, then the script ends... then Ruby segfaults:

I'm on macOS 10.15.7 with ruby 2.5.5, and ruby2d 0.9.5 which is the latest at the time I write this.

The reassignment of the event handler actually works fine (I've checked using a bit more code), the problem is that as soon as assign the key_down event the second time, and I call close and the script reaches its natural end (the "end" at the end is printed) then Ruby crashes with a segfault.

It's not a particularly big issue, since the script ends anyway, but it prevents me from exiting with a shell status of 0.

Is there an easy fix to this issue?