Testing `$?` with `open3#popen3`

exitstatus_test.rb

#!/usr/bin/env ruby

require 'open3'

cmd = 'ls not-a-real-path'
Open3.popen3(cmd) do |stdin, stdout, stderr, wait_thr|
end
p $?

exit_status = nil
Open3.popen3(cmd) do |stdin, stdout, stderr, wait_thr|
    exit_status = wait_thr.value
end
p exit_status

gistfile1.txt

$ rvm use 1.9.3
Using /home/jhoblitt/.rvm/gems/ruby-1.9.3-p448
$ ruby --version
ruby 1.9.3p448 (2013-06-27 revision 41675) [x86_64-linux]
$ ruby exitstatus_test.rb
nil
#<Process::Status: pid 1163 exit 2>

$ rvm use 2.0.0
Using /home/jhoblitt/.rvm/gems/ruby-2.0.0-p247
$ ruby --version
ruby 2.0.0p247 (2013-06-27 revision 41674) [x86_64-linux]
$ ruby exitstatus_test.rb
nil
#<Process::Status: pid 1313 exit 2>

$ rvm use 1.9.3
Using /Users/csanchez/.rvm/gems/ruby-1.9.3-p448
$ ruby exitstatus_test.rb
nil
#<Process::Status: pid 72645 exit 1>
$ rvm use ruby-2.0.0-p195
Using /Users/csanchez/.rvm/gems/ruby-2.0.0-p195
$ ruby exitstatus_test.rb
nil
#<Process::Status: pid 72885 exit 1>