As reported on ycombinator (noted via The Rakudo Weekly News), there appears to be an issue with our Hello World exercise.
I had a go and the default stub appears to crash fairly quickly with the catchall timeout notice:
An error occurred
An error occurred while running your tests. This might mean that there was an issue in our infrastructure, or it might mean that you have something in your code that’s causing our systems to break.
Please check your code, and if nothing seems to be wrong, try running the tests again.