raise

Raises an exception (see Kernel::raise) from thr. The caller does not have to be thr.

Thread.abort_on_exception = true
a = Thread.new { sleep(200) }
a.raise("Gotcha")

produces:

prog.rb:3: Gotcha (RuntimeError)
 from prog.rb:2:in `initialize'
 from prog.rb:2:in `new'
 from prog.rb:2