The hello world example relies on being able to exit the container attachment using Control-C without stopping it. According to this thread (and my own experience), this doesn't work anymore:
https://groups.google.com/forum/#!msg/docker-user/nWXAnyLP9-M/kbv-FZpF4rUJ
Added -sig-proxy=false to the attach command.
Upstream-commit: c9cebf3a73efa4827d051ddd69a8590b03419f8a
Component: engine