Trying that I get some weird error

```
Received exception: No headers to parse:
/usr/bin/gen_bridge_metadata:883:in `prepare'
/usr/bin/gen_bridge_metadata:721:in `parse'
/usr/bin/gen_bridge_metadata:2283
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/optparse.rb:791:in `initialize'
/usr/bin/gen_bridge_metadata:2214:in `new'
/usr/bin/gen_bridge_metadata:2214
No headers to parse
Usage: gen_bridge_metadata [options] <headers...>
Use the `-h' flag or consult gen_bridge_metadata(1) for help.
rake aborted!
```