That's a fantastic idea (not sure why I didn't think of it), but it sadly doesn't work :(.  It gets stuck in `stop`, with the following backtrace (obtained by adding `trap('USR2') { puts caller.join("\n") }` and sending the process the USR2 signal):

```
/Users/myron/.rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/monitor.rb:185:in `call'
/Users/myron/.rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/monitor.rb:185:in `lock'
/Users/myron/.rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/monitor.rb:185:in `mon_enter'
/Users/myron/.rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/monitor.rb:209:in `mon_synchronize'
/Users/myron/moz/qless/bundle/ruby/1.9.1/gems/redis-3.0.4/lib/redis.rb:36:in `synchronize'
/Users/myron/moz/qless/bundle/ruby/1.9.1/gems/redis-3.0.4/lib/redis.rb:1944:in `unsubscribe'
/Users/myron/moz/qless/lib/qless/subscriber.rb:50:in `stop'
/Users/myron/moz/qless/spec/integration/subscriber_spec.rb:60:in `block (2 levels) in <module:Qless>'
```