SIGINT doesn't behave the same as SIPp (or cleanly exit)

[benlangfeld]

vagrant@loadtest:/vagrant$ sippy_cup -cr scenario.yml
Compiling media to /vagrant/scenario.xml...done.
Compiling scenario to /vagrant/scenario.pcap...done.
I, [2013-09-12T17:37:02.967913 #15808]  INFO -- : Preparing to run SIPp command: sudo sipp -i 10.203.175.15 -p 8836 -sf /vagrant/scenario.xml -l 50 -m 5000 -r 10 -s 1 asterisk.local-dev.mojolingo.com > /dev/null 2>&1
^C/home/vagrant/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sippy_cup-0.2.3/lib/sippy_cup/runner.rb:62:in `rescue in run': Command sudo sipp -i 10.203.175.15 -p 8836 -sf /vagrant/scenario.xml -l 50 -m 5000 -r 10 -s 1 asterisk.local-dev.mojolingo.com > /dev/null 2>&1 failed (RuntimeError)
    from /home/vagrant/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sippy_cup-0.2.3/lib/sippy_cup/runner.rb:58:in `run'
    from /home/vagrant/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sippy_cup-0.2.3/bin/sippy_cup:77:in `<top (required)>'
    from /home/vagrant/.rbenv/versions/1.9.3-p448/bin/sippy_cup:23:in `load'
    from /home/vagrant/.rbenv/versions/1.9.3-p448/bin/sippy_cup:23:in `<main>'