interrupt.rb

$ready = false
thread = Thread.new do
  loop do
    $ready = true
    begin
      Thread.pass
    rescue => e
      p e
    ensure
      Thread.handle_interrupt(Object => :never) do # backtrace reports it happens here
        begin
          Thread.pass
        rescue => e
          abort "ensure saw #{e}"
        end
      end
    end
  end
end

1000.times {
  Thread.pass until $ready
  thread.raise "timeout"
  Thread.pass
}

results.txt

ruby -v interrupt.rb |& cat
ruby 3.0.1p64 (2021-04-05 revision 0fb782ee38) [x86_64-linux]
#<RuntimeError: timeout>
#<Thread:0x00000000025c32b0 interrupt.rb:2 run> terminated with exception (report_on_exception is true):
interrupt.rb:10:in `handle_interrupt': timeout (RuntimeError)
	from interrupt.rb:10:in `ensure in block (2 levels) in <main>'
	from interrupt.rb:10:in `block (2 levels) in <main>'
	from interrupt.rb:3:in `loop'
	from interrupt.rb:3:in `block in <main>'