at_exit callback ordering

at_exit.rb

# The purpose of this experiment is to see if we can force our at_exit handler
# to be the very last one invoked regardless of the order in which the at_exit
# handlers are registered. The Ruby documentation states that the at_exit
# handlers are called in the reverse order in which they are registered. So
# the first one registered is the last one called.

at_exit { STDOUT.puts "first" }

at_exit {
 STDOUT.puts "second"
 at_exit { STDOUT.puts "LAST ONE!!" }
}

at_exit { STDOUT.puts "thrid" }

STDOUT.puts "exiting"


=begin ---- output ----

exiting
thrid
second
first
LAST ONE!!

=end

There are some issues about this on Redmine. I think it changed in 1.9.3 (or maybe 1.9.2).