Soxer is currently broken
Soxer does not work with Sinatra 1.2.3.
I have not yet figured out what is going on, so stay put. For production use, do not use the latest version of Sinatra. We are working on a quick fix to be released in 0.9.11 version. Quick fix will also be available on Github even before the official 0.9.11 release.
Stay tuned.