Net ssh users - Feb 2007 - channel.send_signal always returns failed

Hi,

I''m trying to send a signal (SIGINT) to a couple of processes started
asynchronously, but they always return failed. The code looks like
this:

def run_executable (session, executable, args)
    session.open_channel do |channel|
         channel.on_data do |ch, data|
            puts "[#{ch}] ==> #{data}"
            channel.send_signal(''INT'', true)
         end
         channel.on_failure do |ch|
            puts "#{ch} failed"
         end
         channel.on_success do|ch|
            puts "#{ch} successfully opened"
         end
         channel.exec "#{executable} #{args}"
    end
end

What am I doing wrong?

-Vivek