hoxworth/json-schema — comment on commit 2ff929645217a300875b5f3e5b0aabddfbf33c1a
File: lib/json-schema.rb line 16
By hoxworth:

So, in my testing, MultiJson wasn't actually loading the Yajl / JSON gem libs, and was defaulting to the ok_json parser. Perhaps by vendoring the lib it broke the default loading somehow? Anyway, I'll be taking this out with a patch later today to remove the vendoring of MultiJSON.