Yes. Uncommented, it says:

```
bin/htmlproof:8:in `block in <main>': uninitialized constant HTML::Proofer::VERSION (NameError)
	from /opt/boxen/rbenv/versions/2.0.0-github6/lib/ruby/gems/2.0.0/gems/mercenary-0.2.0/lib/mercenary.rb:19:in `program'
	from bin/htmlproof:7:in `<main>'
[commandline-ify]* ~/Development/html-proofer $ 
```