Error when executing system() in Signal.trap

[lucas-clemente]

The following watchr file

system('echo')
Signal.trap 'QUIT' do
  system('echo')
end

Throws an exception when triggering the signal:

^\/Volumes/HDD/data/lucas/test/watchr/watchr.rb:3:in `system': native_thread_join() failed (11) (ThreadError)
    from /Volumes/HDD/data/lucas/test/watchr/watchr.rb:3:in `block in parse!'
    from /Volumes/HDD/data/lucas/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/gems/1.9.1/gems/ruby-fsevent-0.2.1/lib/fsevent/signal_ext.rb:19:in `call'
    from /Volumes/HDD/data/lucas/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/gems/1.9.1/gems/ruby-fsevent-0.2.1/lib/fsevent/signal_ext.rb:19:in `handle'
    from /Volumes/HDD/data/lucas/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/gems/1.9.1/gems/watchr-0.7/lib/watchr/event_handlers/darwin.rb:40:in `start'
    from /Volumes/HDD/data/lucas/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/gems/1.9.1/gems/watchr-0.7/lib/watchr/event_handlers/darwin.rb:40:in `listen'
    from /Volumes/HDD/data/lucas/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/gems/1.9.1/gems/watchr-0.7/lib/watchr/controller.rb:42:in `run'
    from /Volumes/HDD/data/lucas/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/gems/1.9.1/gems/watchr-0.7/bin/watchr:104:in `<top (required)>'
    from /Volumes/HDD/data/lucas/.rvm/rubies/ruby-1.9.3-p194/bin/watchr:23:in `load'
    from /Volumes/HDD/data/lucas/.rvm/rubies/ruby-1.9.3-p194/bin/watchr:23:in `<main>'

I'm using ruby 1.9.3p194 (2012-04-20 revision 35410) [x86_64-darwin10.8.0] on Mac OS 10.6.8.

[lucas-clemente]

All of the lines in the above are necessary, when I remove the first system call it works.